Multi-cell masks and methods and apparatus for using such masks to form three-dimensional structures

ABSTRACT

Multilayer structures are electrochemically fabricated via depositions of one or more materials in a plurality of overlaying and adhered layers. Selectivity of deposition is obtained via a multi-cell controllable mask. Alternatively, net selective deposition is obtained via a blanket deposition and a selective removal of material via a multi-cell mask. Individual cells of the mask may contain electrodes comprising depositable material or electrodes capable of receiving etched material from a substrate. Alternatively, individual cells may include passages that allow or inhibit ion flow between a substrate and an external electrode and that include electrodes or other control elements that can be used to selectively allow or inhibit ion flow and thus inhibit significant deposition or etching. Single cell masks having a cell size that is smaller or equal to the desired deposition resolution may also be used to form structures.

RELATED APPLICATIONS

This application is a continuation of U.S. Non-Provisional patentapplication Ser. No. 10/677,546, filed Oct. 1, 2003 which in turn claimsbenefit to U.S. Provisional Patent Application 60/429,485, filed Nov.26, 2002 and to U.S. Provisional Patent Application 60/415,369, filedOct. 1, 2002. These patent applications along with all other mentionedherein are incorporated herein by reference as if set fourth in full.

FIELD OF THE INVENTION

The present invention relates generally to the field ofthree-dimensional structure fabrication. In some embodiments, meso-scaleor microscale structures are formed via electrochemical operations (e.g.Electrochemical Fabrication or EFAB™ processes, such as electrochemicaldeposition operations and/or etching operations). In some embodimentsthe structures are formed via deposition of a single layer of materialwhile in other embodiments the structures are formed via alayer-by-layer build up of deposited materials. In particular, selectivepatterning of effective deposition regions occurs via one or more maskshaving independently controllable regions.

BACKGROUND

A technique for forming three-dimensional structures (e.g. parts,components, devices, and the like) from a plurality of adhered layerswas invented by Adam L. Cohen and is known as ElectrochemicalFabrication. It is being commercially pursued by Microfabrica Inc.(formerly MEMGen® Corporation) of Burbank, Calif. under the name EFAB™.This technique was described in U.S. Pat. No. 6,027,630, issued on Feb.22, 2000. This electrochemical deposition technique allows the selectivedeposition of a material using a unique masking technique that involvesthe use of a mask that includes patterned conformable material on asupport structure that is independent of the substrate onto whichplating will occur. When desiring to perform an electrodeposition usingthe mask, the conformable portion of the mask is brought into contactwith a substrate while in the presence of a plating solution such thatthe contact of the conformable portion of the mask to the substrateinhibits deposition at selected locations. For convenience, these masksmight be generically called conformable contact masks; the maskingtechnique may be generically called a conformable contact mask platingprocess. More specifically, in the terminology of Microfabrica Inc.(formerly MEMGen® Corporation) of Burbank, Calif. such masks have cometo be known as INSTANT MASKS™ and the process known as INSTANT MASKING™or INSTANT MASK™ plating. Selective depositions using conformablecontact mask plating may be used to form single layers of material ormay be used to form multi-layer structures. The teachings of the '630patent are hereby incorporated herein by reference as if set forth infull herein. Since the filing of the patent application that led to theabove noted patent, various papers about conformable contact maskplating (i.e. INSTANT MASKING) and electrochemical fabrication have beenpublished:

(1) A. Cohen, G. Zhang, F. Tseng, F. Mansfeld, U. Frodis and P. Will,“EFAB: Batch production of functional, fully-dense metal parts withmicro-scale features”, Proc. 9th Solid Freeform Fabrication, TheUniversity of Texas at Austin, p 161, August 1998.

(2) A. Cohen, G. Zhang, F. Tseng, F. Mansfeld, U. Frodis and P. Will,“EFAB: Rapid, Low-Cost Desktop Micromachining of High Aspect Ratio True3-D MEMS”, Proc. 12th IEEE Micro Electro Mechanical Systems Workshop,IEEE, p 244, January 1999.

(3) A. Cohen, “3-D Micromachining by Electrochemical Fabrication”,Micromachine Devices, March 1999.

(4) G. Zhang, A. Cohen, U. Frodis, F. Tseng, F. Mansfeld, and P. Will,“EFAB: Rapid Desktop Manufacturing of True 3-D Microstructures”, Proc.2nd International Conference on Integrated MicroNanotechnology for SpaceApplications, The Aerospace Co., April 1999.

(5) F. Tseng, U. Frodis, G. Zhang, A. Cohen, F. Mansfeld, and P. Will,“EFAB: High Aspect Ratio, Arbitrary 3-D Metal Microstructures using aLow-Cost Automated Batch Process”, 3rd International Workshop on HighAspect Ratio MicroStructure Technology (HARMST'99), June 1999.

(6) A. Cohen, U. Frodis, F. Tseng, G. Zhang, F. Mansfeld, and P. Will,“EFAB: Low-Cost, Automated Electrochemical Batch Fabrication ofArbitrary 3-D Microstructures”, Micromachining and MicrofabricationProcess Technology, SPIE 1999 Symposium on Micromachining andMicrofabrication, September 1999.

(7) F. Tseng, G. Zhang, U. Frodis, A. Cohen, F. Mansfeld, and P. Will,“EFAB: High Aspect Ratio, Arbitrary 3-D Metal Microstructures using aLow-Cost Automated Batch Process”, MEMS Symposium, ASME 1999International Mechanical Engineering Congress and Exposition, November,1999.

(8) A. Cohen, “Electrochemical Fabrication (EFABTM)”, Chapter 19 of TheMEMS Handbook, edited by Mohamed Gad-EI-Hak, CRC Press, 2002.

“(9) Microfabrication—Rapid Prototyping's Killer Application”, pages 1-5of the Rapid Prototyping Report, CAD/CAM Publishing, Inc., June 1999.

The disclosures of these nine publications are hereby incorporatedherein by reference as if set forth in full herein.

The electrochemical deposition process may be carried out in a number ofdifferent ways as set forth in the above patent and publications. In oneform, this process involves the execution of three separate operationsduring the formation of each layer of the structure that is to beformed:

1. Selectively depositing at least one material by electrodepositionupon one or more desired regions of a substrate.

2. Then, blanket depositing at least one additional material byelectrodeposition so that the additional deposit covers both the regionsthat were previously selectively deposited onto, and the regions of thesubstrate that did not receive any previously applied selectivedepositions.

3. Finally, planarizing the materials deposited during the first andsecond operations to produce a smoothed surface of a first layer ofdesired thickness having at least one region containing the at least onematerial and at least one region containing at least the one additionalmaterial.

After formation of the first layer, one or more additional layers may beformed adjacent to the immediately preceding layer and adhered to thesmoothed surface of that preceding layer. These additional layers areformed by repeating the first through third operations one or more timeswherein the formation of each subsequent layer treats the previouslyformed layers and the initial substrate as a new and thickeningsubstrate.

Once the formation of all layers has been completed, at least a portionof at least one of the materials deposited is generally removed by anetching process to expose or release the three-dimensional structurethat was intended to be formed.

The preferred method of performing the selective electrodepositioninvolved in the first operation is by conformable contact mask plating.In this type of plating, one or more conformable contact (CC) masks arefirst formed. The CC masks include a support structure onto which apatterned conformable dielectric material is adhered or formed. Theconformable material for each mask is shaped in accordance with aparticular cross-section of material to be plated. At least one CC maskis needed for each unique cross-sectional pattern that is to be plated.

The support for a CC mask is typically a plate-like structure formed ofa metal that is to be selectively electroplated and from which materialto be plated will be dissolved. In this typical approach, the supportwill act as an anode in an electroplating process. In an alternativeapproach, the support may instead be a porous or otherwise perforatedmaterial through which deposition material will pass during anelectroplating operation on its way from a distal anode to a depositionsurface. In either approach, it is possible for CC masks to share acommon support, i.e. the patterns of conformable dielectric material forplating multiple layers of material may be located in different areas ofa single support structure. When a single support structure containsmultiple plating patterns, the entire structure is referred to as the CCmask while the individual plating masks may be referred to as“submasks”. In the present application such a distinction will be madeonly when relevant to a specific point being made.

In preparation for performing the selective deposition of the firstoperation, the conformable portion of the CC mask is placed inregistration with and pressed against a selected portion of thesubstrate (or onto a previously formed layer or onto a previouslydeposited portion of a layer) on which deposition is to occur. Thepressing together of the CC mask and substrate occur in such a way thatall openings, in the conformable portions of the CC mask contain platingsolution. The conformable material of the CC mask that contacts thesubstrate acts as a barrier to electrodeposition while the openings inthe CC mask that are filled with electroplating solution act as pathwaysfor transferring material from an anode (e.g. the CC mask support) tothe non-contacted portions of the substrate (which act as a cathodeduring the plating operation) when an appropriate potential and/orcurrent are supplied.

An example of a CC mask and CC mask plating are shown in FIGS.1(a)-1(c). FIG. 1(a) shows a side view of a CC mask 8 consisting of aconformable or deformable (e.g. elastomeric) insulator 10 patterned onan anode 12. The anode has two functions. FIG. 1(a) also depicts asubstrate 6 separated from mask 8. One is as a supporting material forthe patterned insulator 10 to maintain its integrity and alignment sincethe pattern may be topologically complex (e.g., involving isolated“islands” of insulator material). The other function is as an anode forthe electroplating operation. CC mask plating selectively depositsmaterial 22 onto a substrate 6 by simply pressing the insulator againstthe substrate then electrodepositing material through apertures 26 a and26 b in the insulator as shown in FIG. 1(b). After deposition, the CCmask is separated, preferably non-destructively, from the substrate 6 asshown in FIG. 1(c). The CC mask plating process is distinct from a“through-mask” plating process in that in a through-mask plating processthe separation of the masking material from the substrate would occurdestructively. As with through-mask plating, CC mask plating depositsmaterial selectively and simultaneously over the entire layer. Theplated region may consist of one or more isolated plating regions wherethese isolated plating regions may belong to a single structure that isbeing formed or may belong to multiple structures that are being formedsimultaneously. In CC mask plating as individual masks are notintentionally destroyed in the removal process, they may be usable inmultiple plating operations.

Another example of a CC mask and CC mask plating is shown in FIGS.1(d)-1(f). FIG. 1(d) shows an anode 12′ separated from a mask 8′ thatincludes a patterned conformable material 10′ and a support structure20. FIG. 1(d) also depicts substrate 6 separated from the mask 8′. FIG.1(e) illustrates the mask 8′ being brought into contact with thesubstrate 6. FIG. 1(f) illustrates the deposit 22′ that results fromconducting a current from the anode 12′ to the substrate 6. FIG. 1(g)illustrates the deposit 22′ on substrate 6 after separation from mask8′. In this example, an appropriate electrolyte is located between thesubstrate 6 and the anode 12′ and a current of ions coming from one orboth of the solution and the anode are conducted through the opening inthe mask to the substrate where material is deposited. This type of maskmay be referred to as an anodeless INSTANT MASK™ (AIM) or as ananodeless conformable contact (ACC) mask.

Unlike through-mask plating, CC mask plating allows CC masks to beformed completely separate from the fabrication of the substrate onwhich plating is to occur (e.g. separate from a three-dimensional (3D)structure that is being formed). CC masks may be formed in a variety ofways, for example, a photolithographic process may be used. All maskscan be generated simultaneously, prior to structure fabrication ratherthan during it. This separation makes possible a simple, low-cost,automated, self-contained, and internally-clean “desktop factory” thatcan be installed almost anywhere to fabricate 3D structures, leaving anyrequired clean room processes, such as photolithography to be performedby service bureaus or the like.

An example of the electrochemical fabrication process discussed above isillustrated in FIGS. 2(a)-2(f). These figures show that the processinvolves deposition of a first material 2 which is a sacrificialmaterial and a second material 4 which is a structural material. The CCmask 8, in this example, includes a patterned conformable material (e.g.an elastomeric dielectric material) 10 and a support 12 which is madefrom deposition material 2. The conformal portion of the CC mask ispressed against substrate 6 with a plating solution 14 located withinthe openings 16 in the conformable material 10. An electric current,from power supply 18, is then passed through the plating solution 14 via(a) support 12 which doubles as an anode and (b) substrate 6 whichdoubles as a cathode. FIG. 2(a), illustrates that the passing of currentcauses material 2 within the plating solution and material 2 from theanode 12 to be selectively transferred to and plated on the cathode 6.After electroplating the first deposition material 2 onto the substrate6 using CC mask 8, the CC mask 8 is removed as shown in FIG. 2(b). FIG.2(c) depicts the second deposition material 4 as having beenblanket-deposited (i.e. non-selectively deposited) over the previouslydeposited first deposition material 2 as well as over the other portionsof the substrate 6. The blanket deposition occurs by electroplating froman anode (not shown), composed of the second material, through anappropriate plating solution (not shown), and to the cathode/substrate6. The entire two-material layer is then planarized to achieve precisethickness and flatness as shown in FIG. 2(d). After repetition of thisprocess for all layers, the multi-layer structure 20 formed of thesecond material 4 (i.e. structural material) is embedded in firstmaterial 2 (i.e. sacrificial material) as shown in FIG. 2(e). Theembedded structure is etched to yield the desired device, i.e. structure20, as shown in FIG. 2(f).

Various components of an exemplary manual electrochemical fabricationsystem 32 are shown in FIGS. 3(a)-3(c). The system 32 consists ofseveral subsystems 34, 36, 38, and 40. The substrate holding subsystem34 is depicted in the upper portions of each of FIGS. 3(a) to 3(c) andincludes several components: (1) a carrier 48, (2) a metal substrate 6onto which the layers are deposited, and (3) a linear slide 42 capableof moving the substrate 6 up and down relative to the carrier 48 inresponse to drive force from actuator 44. Subsystem 34 also includes anindicator 46 for measuring differences in vertical position of thesubstrate which may be used in setting or determining layer thicknessesand/or deposition thicknesses. The subsystem 34 further includes feet 68for carrier 48 which can be precisely mounted on subsystem 36.

The CC mask subsystem 36 shown in the lower portion of FIG. 3(a)includes several components: (1) a CC mask 8 that is actually made up ofa number of CC masks (i.e. submasks) that share a common support/anode12, (2) precision X-stage 54, (3) precision Y-stage 56, (4) frame 72 onwhich the feet 68 of subsystem 34 can mount, and (5) a tank 58 forcontaining the electrolyte 16. Subsystems 34 and 36 also includeappropriate electrical connections (not shown) for connecting to anappropriate power source for driving the CC masking process.

The blanket deposition subsystem 38 is shown in the lower portion ofFIG. 3(b) and includes several components: (1) an anode 62, (2) anelectrolyte tank 64 for holding plating solution 66, and (3) frame 74 onwhich the feet 68 of subsystem 34 may sit. Subsystem 38 also includesappropriate electrical connections (not shown) for connecting the anodeto an appropriate power supply for driving the blanket depositionprocess.

The planarization subsystem 40 is shown in the lower portion of FIG.3(c) and includes a lapping plate 52 and associated motion and controlsystems (not shown) for planarizing the depositions.

In addition to teaching the use of CC masks for electrodepositionpurposes, the '630 patent also teaches that the CC masks may be placedagainst a substrate with the polarity of the voltage reversed andmaterial may thereby be selectively removed from the substrate. Itindicates that such removal processes can be used to selectively etch,engrave, and polish a substrate, e.g., a plaque.

Another method for forming microstructures from electroplated metals(i.e. using electrochemical fabrication techniques) is taught in U.S.Pat. No. 5,190,637 to Henry Guckel, entitled “Formation ofMicrostructures by Multiple Level Deep X-ray Lithography withSacrificial Metal layers”. This patent teaches the formation of metalstructure utilizing mask exposures. A first layer of a primary metal iselectroplated onto an exposed plating base to fill a void in aphotoresist, the photoresist is then removed and a secondary metal iselectroplated over the first layer and over the plating base. Theexposed surface of the secondary metal is then machined down to a heightwhich exposes the first metal to produce a flat uniform surfaceextending across the both the primary and secondary metals. Formation ofa second layer may then begin by applying a photoresist layer over thefirst layer and then repeating the process used to produce the firstlayer. The process is then repeated until the entire structure is formedand the secondary metal is removed by etching. The photoresist is formedover the plating base or previous layer by casting and the voids in thephotoresist are formed by exposure of the photoresist through apatterned mask via X-rays or UV radiation.

Even though electrochemical fabrication as taught and practiced to date,has greatly enhanced the capabilities of microfabrication, and inparticular added greatly to the number of metal layers that can beincorporated into a structure and to the speed and simplicity in whichsuch structures can be made, room for enhancing the state ofelectrochemical fabrication exists. For example, formation of individualmasks for each layer can be expensive and time consuming. Suchindividualized masks must also be recreated for even minor designchanges. A need exists in the field for a simplified manner and lessrestrictive manner for obtaining selective deposition of material in anelectrochemical fabrication process.

SUMMARY OF THE INVENTION

It is an object of various aspects of the present invention to provide aless restrictive technique for obtaining selective deposition ofmaterial.

It is an object of various aspects of the present invention to provide asimplified electrochemical fabrication process.

Other objects and advantages of various aspects of the invention will beapparent to those of skill in the art upon review of the teachingsherein. The various aspects of the invention, set forth explicitlyherein or otherwise ascertained from the teaching herein, may addressany one of the above objects alone or in combination, or alternativelymay address some other object of the invention ascertained from theteachings herein. It is not intended that all of, or necessarily any of,the above objects be addressed by any single aspect of the inventioneven though that may be the case with regard to some aspects.

In a first aspect of the invention a process for forming a multilayerthree-dimensional structure, includes: (a) forming a layer of at leastone material on a substrate that may include one or more previouslydeposited layers of one or more materials; (b) repeating the formingoperation of “(a)” one or more times to form at least one subsequentlayer on at least one previously formed layer to build up athree-dimensional structure from a plurality layers; wherein the formingof at least one layer, includes: (1) supplying a substrate on which oneor more successive depositions of one or more materials may haveoccurred and will occur; (2) supplying a multi-cell mask, wherein eachcell is separated from other cells by a material, wherein the cells ofthe mask include independently controllable electrodes, and wherein apattern of dielectric material extends beyond the cell electrodes forcontacting the substrate and for forming electrochemical process pocketswhen such contact is made; (3) bringing the multi-cell mask and thesubstrate into contact such that electrochemical process pockets areformed having a desired registration with respect to any previousdepositions and providing a desired electrolyte solution such that thesolution is provided within the electrochemical process pockets; and (4)applying a desired electrical activation to desired cell electrodes, tothe substrate, and to any other desired electrodes, such that a desiredmaterial is selectively deposited onto the substrate.

In a second aspect of the invention a process for modifying a substrateincludes: (a) supplying a substrate on which one or more successivedepositions of one or more materials may have occurred; (b) supplying amulti-cell mask, wherein each cell is separated from other cells by amaterial, wherein the cells of the mask include independentlycontrollable electrodes, and wherein a pattern of dielectric materialextends beyond the cell electrodes for contacting the substrate and forforming electrochemical process pockets when such contact is made; (c)bringing the multi-cell mask and the substrate into contact such thatelectrochemical process pockets are formed having a desired registrationwith respect to any previous depositions and providing a desiredelectrolyte solution such that the solution is provided within theelectrochemical process pockets; and (d) applying a desired electricalactivation to at least one desired cell electrode, to the substrate, andto any other desired electrode or electrodes, such that a desiredmaterial is selectively deposited onto the substrate.

In a third aspect of the invention a process for a multi-cell maskincludes: a plurality of independently controllable cells, wherein eachcell is separated from other cells by a material, wherein the cells ofthe mask include independently controllable electrodes, and wherein apattern of dielectric material extends beyond the cell electrodes forcontacting a substrate and for forming electrochemical process pocketswhen such contact is made.

In a fourth aspect of the invention a process for forming a multilayerthree-dimensional structure includes: (a) a substrate on which one ormore successive depositions of one or more materials may have occurred;(b) a mask having multiple cells, wherein each cell is separated fromother cells by a material, wherein the cells of the mask includeindependently controllable electrodes, and wherein a pattern ofdielectric material extends beyond the cell electrodes for contactingthe substrate and for forming electrochemical process pockets when suchcontact is made; (c) a computer controlled stage for bringing themulti-cell mask and the substrate into contact such that electrochemicalprocess pockets are formed having a desired registration with respect toany previous depositions and providing a desired electrolyte solutionsuch that the solution is provided within the electrochemical processpockets; (d) at least one power supply for applying desired electricalpower to the substrate, to selected cell electrodes, and to any otherelectrodes required to cause selective deposition onto the substrate;(e) at least one computer programmed for repeatedly controlling thestage, for controlling selected cell electrodes, and for controlling thesupply of power from the power supply to cause selective deposition ontothe substrate to deposit at least portions of a plurality of layers ofmaterial on previously formed layers when forming a desired structurefrom a plurality of layers.

In a fifth aspect of the invention a process for modifying a substrateincludes: (a) a substrate on which one or more successive depositions ofone or more materials may have occurred and will occur; (b) a maskhaving multiple cells, wherein each cell is separated from other cellsby a material, wherein the cells of the mask include independentlycontrollable electrodes, and wherein a pattern of dielectric materialextends beyond the cell electrodes for contacting the substrate and forforming electrochemical process pockets when such contact is made; (c) astage for bringing the multi-cell mask and the substrate into contactsuch that electrochemical process pockets are formed having a desiredregistration with respect to any previous depositions and providing adesired electrolyte solution such that the solution is provided withinthe electrochemical process pockets; (d) at least one power supply forapplying desired electrical power to the substrate, to selected cellelectrodes, and to any other electrodes required to cause selectivedeposition onto the substrate; (e) at controller for controllingselected cell electrodes and for controlling the supply of power fromthe power supply to cause selective deposition onto the substrate todeposit at least a portion of a layer of material onto the substrate.

Further aspects of the invention will be understood by those of skill inthe art upon reviewing the teachings herein. Other aspects of theinvention may involve apparatus that can be used in implementing one ormore of the above method aspects of the invention. Still other aspectsmay involve use of the multi-cell masks set forth herein for formingsingle layers. Still other aspects of the invention may providemulti-cell masks configured according to the various embodiments setforth herein or generalizations thereof. These other aspects of theinvention may provide various combinations of the aspects presentedabove as well as provide other configurations, structures, functionalrelationships, and processes that have not been specifically set forthabove.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1(a)-1(c) schematically depict side views of various stages of aCC mask plating process, while FIGS. 1(d)-(g) schematically depict aside views of various stages of a CC mask plating process using adifferent type of CC mask.

FIGS. 2(a)-2(f) schematically depict side views of various stages of anelectrochemical fabrication process as applied to the formation of aparticular structure where a sacrificial material is selectivelydeposited while a structural material is blanket deposited.

FIGS. 3(a)-3(c) schematically depict side views of various examplesubassemblies that may be used in manually implementing theelectrochemical fabrication method depicted in FIGS. 2(a)-2(f).

FIGS. 4(a)-4(i) schematically depict the formation of a first layer of astructure using adhered mask plating where the blanket deposition of asecond material overlays both the openings between deposition locationsof a first material and the first material itself.

FIGS. 5(a)-5(c) depict top views of elements of one embodiment of amulti-cell mask.

FIGS. 5(d)-5(f) depicts top views of the resulting depositions from afirst selective activation of the mask, a combined first and shiftedsecond activation, and the result of four activations with the third andfourth being shifted relative to each other and to the first and secondactivations.

FIG. 6(a) depicts a top view of a multi-cell mask having passages thatextend through the cells of the mask and ring electrodes that surroundthe passages, while FIG. 6(b) depicts a side view of the mask of FIG.6(a).

FIG. 6(c) depicts a side view of a mask similar to that of 6(a) and 6(b)but with a cell electrode in the form of a porous medium.

FIG. 7 depicts a side view of a multi-cell mask having passages thatextend through the cells and cell electrodes in the form of rings thatsurround the passages along with other components that would be used inpracticing a particular embodiment of the invention.

FIG. 8(a)-8(b) depict a single cell of a single cell mask or of amulti-cell mask and multiple cells of such a mask, respectively, wherethe openings of the cells have a width that is larger than the width ofthe dielectric that separates them.

FIG. 9(a)-9(b) depict top and side views, respectively, of anintra-region pattern of overlapping depositions.

FIGS. 9(c) and 9(d) depict top and side views, respectively, of aninter-region and intra-region pattern of overlapping depositions.

FIG. 10(a) depicts the opening of one cell of a multi-cell mask wherethe opening width is about one-half the region width or little less.

FIGS. 10(b) and 10(c) depict top and side views, respectively, of asample deposition that may be performed using the mask of FIG. 10(a)where no overlap occurs between adjacent depositions.

FIGS. 11(a)-11(g) provide an example of how cell openings slightlysmaller than the dielectric spacing between openings may be used to formdepositions without overlapping depositions or breaks between adjacentdepositions.

FIGS. 12(a)-12(f) depict some alternative opening configurations andpatterns for masks.

FIGS. 13(a)-13(e) depict a mask containing hexagonal openings spaced ina hexagonal pattern of approximately the same dimensions as the openingsand an associated three-step non-overlapping deposition pattern that maybe used with such a mask.

FIGS. 14(a)-14(e) depict a mask containing square openings spaced in apartially staggered pattern of approximately the same dimensions as theopenings and an associated three-step non-overlapping deposition patternthat may used with such a mask.

FIGS. 15(a)-15(e) depict a mask containing hexagonal openings spaced ina hexagonal pattern where the spacing between openings is less the widthof the openings and an associated three-step overlapping depositionpattern that may used with such a mask.

FIG. 16(a)-16(d) depict two complementary masks with triangular shapedopenings along with an associated two step deposition pattern that maybe used with such a mask.

FIGS. 17(a)-17(d) depict a mask with square openings arranged in acheckerboard pattern along with an associated two step depositionpattern that may be used with such a mask.

FIGS. 18(a)-18(d) depict deposition locations for each of four offsetsof a mask that is similar to that shown in FIGS. 8(a) and 8(b) where theresulting net deposition pattern is similar to that of FIGS. 9(a) and9(b).

FIGS. 19(a)-19(d) provide combined deposition height accounting for eachof the four steps of FIGS. 18(a)-18(d) across the region that the cellcovers.

FIGS. 20 and 21 depict top views of a single cell of a multi-cell maskand multiple cells of such a mask, respectively, where the cell size andpattern of cells may be used in an etching operation to remove materialfrom regions of overlapped deposits.

FIG. 22 depicts a sample pattern that might be deposited by six cells ofa multi-cell mask making depositions similar to that of FIG. 19(d) wherefour of the cells actively participate in the deposition.

FIG. 23 depicts the sample deposits of FIG. 22 after a single etchingoperation using the mask of FIG. 21 to reduce the height of the tallestdeposition.

FIGS. 24(a) and 24(b) depict sample mask configurations and patternsthat might be used in further etching material from an overlappingpattern of deposits like that shown in FIG. 23.

FIG. 25 depicts a side view of a multi-cell mask where the cells includecontrol elements that may be used to form bubbles that can inactivateselected cells.

FIG. 26 depicts use of the multi-cell mask of FIG. 25 with two of thecells inactivated.

FIG. 27 depicts the deposit that resulted from the operation illustratedin FIG. 26.

FIG. 28 depicts use of the multi-cell mask of FIG. 25 with one of thecells inactivated.

FIG. 29 depicts a side view of the deposit that resulted from theoperation of FIG. 28

FIG. 30 depicts an alternative version of a multi-cell mask where thedielectric dividers do not extend beyond the functional cell componentsbut instead bubble generators may be used to form dividers betweenselected cells.

FIG. 31 depicts use of a multi-cell mask that doesn't use dividers thatextend beyond the level of the electrodes.

FIGS. 32(a)-32(d) depict a process for changing the height of selecteddielectric separators according to an embodiment of the invention wherethe dividers include a material whose shape can be modified.

FIGS. 33(a)-33(b) depict a process for changing the height of selecteddielectric dividers according to an embodiment of the invention wherematerial is transferred to the dividers.

FIGS. 34(a)-34(c) depict a process for forming a pattern over thedielectric dividers to modify the contact area of a multi-cell mask.

FIGS. 35(a)-35(f) depict side views of structures exemplifying exampleof different overlay patterns that might result from using multi-cellmasks with different sized openings and/or by changing the relativepositioning of deposition locations periodically.

FIGS. 36(a)-36(d) illustrate some aspects of multi-cell mask use inmulti-step etching operations.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

FIGS. 1(a)-1(g), 2(a)-2(f), and 3(a)-3(c) illustrate various features ofone form of electrochemical fabrication that are known. Otherelectrochemical fabrication techniques are set forth in the '630 patentreferenced above, in the various previously incorporated publications,in various other patents and patent applications incorporated herein byreference, still others may be derived from combinations of variousapproaches described in these publications, patents, and applications,or are otherwise known or ascertainable by those of skill in the artfrom the teachings set forth herein. All of these techniques may becombined with those of the various embodiments of various aspects of theinvention to yield enhanced embodiments. Still other embodiments may bederived from combinations of the various embodiments explicitly setforth herein.

FIGS. 4(a)-4(i) illustrate various stages in the formation of a singlelayer of a multi-layer fabrication process where a second metal isdeposited on a first metal as well as in openings in the first metalwhere its deposition forms part of the layer. In FIG. 4(a), a side viewof a substrate 82 is shown, onto which patternable photoresist 84 iscast as shown in FIG. 4(b). In FIG. 4(c), a pattern of resist is shownthat results from the curing, exposing, and developing of the resist.The patterning of the photoresist 84 results in openings or apertures92(a)-92(c) extending from a surface 86 of the photoresist through thethickness of the photoresist to surface 88 of the substrate 82. In FIG.4(d), a metal 94 (e.g. nickel) is shown as having been electroplatedinto the openings 92(a)-92(c). In FIG. 4(e), the photoresist has beenremoved (i.e. chemically stripped) from the substrate to expose regionsof the substrate 82 which are not covered with the first metal 94. InFIG. 4(f), a second metal 96 (e.g., silver) is shown as having beenblanket electroplated over the entire exposed portions of the substrate82 (which is conductive) and over the first metal 94 (which is alsoconductive). FIG. 4(g) depicts the completed first layer of thestructure which has resulted from the planarization of the first andsecond metals down to a height that exposes the first metal and sets athickness for the first layer. In FIG. 4(h) the result of repeating theprocess steps shown in FIGS. 4(b)-4(g) several times to form amulti-layer structure are shown where each layer consists of twomaterials. For most applications, one of these materials is removed asshown in FIG. 4(i) to yield a desired 3-D structure 98 (e.g. componentor device).

The various embodiments, alternatives, and techniques disclosed hereinmay be used in combination with electrochemical fabrication techniquesthat use different types of patterning masks and masking techniques oreven techniques that perform direct selective depositions without theneed for masking. For example, conformable contact masks and maskingoperations may be used, proximity masks and masking operations (i.e.operations that use masks that at least partially selectively shield asubstrate by their proximity to the substrate even if contact is notmade) may be used, non-conformable masks and masking operations (i.e.masks and operations based on masks whose contact surfaces are notsignificantly conformable) may be used, and adhered masks and maskingoperations (masks and operations that use masks that are adhered to asubstrate onto which selective deposition or etching is to occur asopposed to only being contacted to it) may be used.

A simple example of a controllable multi-cell mask and a sampledeposition created therefrom is illustrated in FIGS. 5(a)-5(f).Electrochemical Fabrication using such programmable multi-cell masks maybe termed Direct-Write™ EFAB™”. As the masks may be controlled toprovide many different deposition patterns, they may be termed “smartmasks”. Utilization of smart masks eliminates the need for structurespecific masks; however, in some embodiments a combination of smartmasks and structure specific masks may be used as the structure ordevice specific masks may still offer some advantages in terms ofsurface resolution and smoothness. In some embodiments, a smart mask,may be based on a smart anode, which includes a plurality of individualsubanodes 102(1,1) to 102(7,7), arranged in a 2-D matrix and separatedby a dielectric 104. An example of such a multi-cell anode is depictedin FIG. 5(a). Each subanode may be individually turned on and off. Thecontrol of the individual subanodes may be achieved, for example, byfabricating the array of subanodes over an integrated circuit, and usingtransistors in the circuit to control current to the subanodes. This canbe done, for example, using flip-flops at each subanode location. Thesubanodes may be supported in position by other structures (not shown)which may, for example, include a solid dielectric material locatedbetween each subanode or connecting the back sides of each subanode.

In some embodiments the array of subanodes is covered with a patternedelastomeric material that extends beyond the plane of the electrodessuch that a pocket is formed around each anode having a width thatestablishes the effective size of the anode and a depth (e.g. as smallas 10 microns, or less, to as large as one to several hundred microns,or even larger) appropriate for holding an electrolyte and allowing adesired electrochemical reaction to occur. The regions defined by theanode, the dielectric may be considered the cells of the mask, in thisembodiment, and regions additionally defined by a substrate to which themask is positioned in proximity to or brought into contact with, may beconsidered as process pockets associated with the cells of the mask Eachanode may be formed of the desired material to be deposited (e.g.copper) or it may be formed of a non-erodable conductor (e.g. platinumor highly doped silicon) on which a quantity of deposition material isplaced. A pattern of elastomeric material 114 is illustrated in FIG.5(b) where openings 112(1,1) to 112(7,7) are formed which help definethe cells of the mask. FIG. 5(c) illustrates the elastomeric material114 overlaying the anodes 102(1,1) to 102(7,7). The type of smart maskillustrated in FIGS. 5(a) to 5(c) may be termed a “mask-on-anode” (MOA)mask for conformable contact masking or proximity masking.

In other embodiments, the elastomeric material may be replaced by aconformable material that is non-elastomeric or by even a material thatis relatively rigid without significant conformability. In embodimentswhere a rigid contact material is used there may be an increasedlikelihood of flash which may be removed or reduced by application of aselective etching operation or by a relatively short or gentle bulketching operation of the electrochemical or chemical type. Inembodiments where a relatively rigid contact material is used,flexibility across the width of the mask may be obtained by a supportstructure, that connects some or all of the anodes together, having someflexibility or by a more conformable material being located between theanodes and the contact material. Such alternatives for providing overallflexibility to a mask that uses a relatively rigid contact material arefurther described in U.S. Provisional Application No. 60/429,484 filedNov. 26, 2003 by Cohen et al, and entitled “Non-Conformable Masks andMethods and Apparatus for Forming Three-Dimensional Structures”. Thisapplication is incorporated herein by reference.

In some embodiments, the mask may include a dielectric material that isdisassociated from the rest of the mask (e.g. electrodes and separatingdielectric). In these alternative embodiments the disassociateddielectric may be patterned onto a substrate or previously depositedmaterial. It may be planed (if necessary, e.g. by machining or lapping)and patterned in a desired manner. The patterning of the disassociateddielectric material may define cells of similar resolution to thatdefined by the separate portion of the mask. Such embodiments maybenefit from accurate placement of the disassociated masks but may notrequire as accurate a placement of the portion of the mask that containsthe electrodes as slight misplacements of the two may have littlenegative impact on the deposited or etched material. Examples ofmaterials that may be used to form such disassociated masks includeliquid photoresists (of the negative or positive type), dry filmphotoresists (of the negative or positive type), and photopolymers.Patterning of such materials may occur via normal exposure throughphotomasks followed by development, direct scanned UV laser exposurefollowed by development, or even direct laser ablation. An advantage tosuch an approach is that a single photomask or a small set of photomasksmay be used to produce a wide range of structures.

As noted above each anode of the smart mask is independently controlled.This may be achieved, for example, through its formation on anintegrated circuit that offers control capability or through conductivepaths that lead from the back side of the mask, or through thedielectric material located between the subanodes, to appropriatecontrol circuitry. In still further alternatives, control may beprovided via a reduced set of control lines via multiplexedconfiguration of control lines and circuitry. The multiplexer may powerindividual cells directly or it may supply power to storage capacitors,or the like, associated with each cell which in turn supplies a steadierlevel of current and/or potential to selected subanodes.

When the mask is pressed against a substrate and the subanodes areturned on in a specific pattern, a selective deposit of that patternoccurs. FIG. 5(d) illustrates an example of a selective deposit pattern122 over a substrate 120 that forms a portion of a letter “E” pattern.By relatively shifting the substrate and mask positions to threeadditional offset positions and repeating the same deposition pattern, acompleted pattern is deposited. FIG. 5(e) illustrates the depositionpattern 324 that results after the second positioning and depositionoperation. FIG. 5(f) illustrates the completed pattern 126 after allfour depositions.

In other embodiments, the offsetting and deposition patterns could havebeen performed using more than four sets of operations (e.g.positioning, seating, and deposition operations) and/or differentdeposition patterns could have been used after each positioningoperation. If the required final deposition pattern allowed it, fewerthan four sets of operations could have been performed. Deposits such asthat in FIG. 5(f), since they result from the overlap of individualpatterns, are continuous in the substrate plane. However, because of theoverlap, they are of non-uniform thickness (thicker in the area ofoverlap). The non-uniformity in thickness may be removed by aplanarization operation (and potentially other clean up operations)either prior to the completion of all depositions for a given layer orafter completion of all deposition for the layer (e.g. before or after ablanket or other deposition that deposits a final material for thelayer).

In alternative embodiments, the subanode dimensions, the subanodespacing, and the positioning accuracy associated with the offsets may beselected such that little or no overlap occurs between successivedepositions, i.e. between pattern filling depositions, associated withforming a given layer. In still further alternative embodiments,different smart masks having different deposition patterns or sizes maybe used for successive (i.e. shifted) depositions such that overlap isminimized while still ensuring lateral contact between deposits.

Subanodes may be periodically “redressed” so that the mask can be usedmultiple times. In the case of a multi-cell mask that is used fordeposition, redressing may occur by plating deposition material onto thesubanodes. Prior to beginning a redressing operation, if the subanodesare formed of a non-erodable material (e.g. platinum or silicon), anyremaining deposition material on the subanodes to be redressed can beremoved and then redressing can begin with a known starting point. Insome embodiments, the extended dielectric material is preferably notmounted to the erodable material but in other embodiments it may be. Insome embodiments, the extended dielectric material is mounted to asecond dielectric that separates the electrodes from another oralternatively is mounted to a combination of a second dielectric and anon-erodable conductive material where the depositable material isplated onto the non-erodable material within the cells defined by theextended dielectric material.

It can be determined which subanodes should be redressed, andpotentially by how much, by simply tracking their deposit historyindividually. Alternatively, the subanodes may be tested periodically toensure that they are working properly. For example, a test may beperformed before a deposition onto a substrate and after a depositiononto the substrate. If the prior test showed that each subanode wasworking correctly, the subanode is used for the deposition onto thesubstrate. If after deposition, the subanodes are retested, and it isfound that one or more of the anodes failed the test then selecteddepositions on the substrate can be examined for their appropriatenessand/or the deposition on the substrate can be removed and theselectively deposition operation repeated with a different mask, withthe same mask but after redressing, or deposition to only selectedportions of the substrate can be repeated but this time using differentcells of the mask.

Cells that remain defective, even after attempts to redress them, may beflagged and their use avoided during successive plating operations orotherwise compensated for by performing additional plating operationswith offsets to position working cells to positions previously occupiedby the faulty cells.

While the use of N exposures (e.g. 4 exposures) will result in an N-fold(e.g. fourfold), or more, increase in deposition time compared with EFABusing structure specific masks, overall process time may not increase bysuch a large factor as the process typically includes other operationsas well. If the EFAB process is similar to that set forth in thebackground (i.e. with one blanket deposition operation and oneplanarization operation per layer), the overall process time, forexample if four exposures are used will probably not double.

In preferred embodiments, the elastomer is thick and/or compliant enoughthat it can accommodate for the thickness of a deposit generated duringa previous exposure (i.e. previous deposition) and still provide goodmasking with minimal and preferably no flash as the mask attempts tomate over any discontinuity between the deposit and the substrate below.To minimize the effects of large discontinuities, planarizationoperations can occur more frequently than once per layer.

In alternative embodiments, discontinuities may be minimized by onlymaking partial layer thickness depositions per pass and then repeatingthe four or more steps a plurality of times (this may be termed“cycling”). It may be beneficial to implement cycling when layerthickness is above 1-2 microns such that the thickness added by anysingle deposition remains under about 1 micron.

In other alternative embodiments, instead of using the multi-cell maskto perform deposition operations, the multi-cell mask may be used toperform etching operations. In these alternatives, much of the abovediscussion still applies but the cells of the mask no-longer containssubanodes but instead may be considered to contain subcathodes. Suchmasks may be considered to be of the Mask-on-Cathode (MOC) type.

Differential in deposition height or etching depth from an active cellmay occur due to differential amounts of time that different portions ofthe region are exposed to deposition or etching conditions. As a cell isshifted through its four or more deposition positions, if there is someoverlap between the positions (e.g. near the center of the region) theoverlapped regions will receive a different amount of deposition oretching than the non-overlapped regions. Differential in deposition maynot matter in a build process that will include a planarizationoperation on each layer.

However, when planarization is not to occur on each layer, it may bedesirable to even out the deposition thickness. This evening out mayoccur in a multi-cell selective deposition embodiment by etching withone or more additional multi-cell masks (e.g. a second mask and possiblya third mask or even a fourth multi-cell mask) where the cell patternsand positions of these patterns are set to correspond to the regions ofoverlap (e.g. quadruple overlap, double overlap, and the like). Inembodiments where the resolution is considered to correspond to theapproximate area that is to be covered by each cell (i.e. a given cellis either off or on for all exposures of a deposition and offsettingpattern), as the overlap positions associated with cells are dictated bythe cell shape and the offsetting technique used, these overlap patternswill have fixed shapes that can be accommodated by only one or a fewadditional masks. For example if it is desired to bring the netdeposition height down to approximately the deposition thicknessassociated with the non-overlapped region, then the quadruple overlapmask may be used to etch the quadruple exposed region down to the levelof a double exposure, while the double overlap mask may include thequadruple overlap region and it may be used to reduce the thickness downto the non-overlap thickness.

Differentials in etching depth within a given cell's etching region mayalso be problematic and may require intervention using multi-cells maskshaving cell configurations that correspond to different etching overlaplevels (quadruple overlap, double overlap, and like). These additionalmasks may be used to plate material into the over etched regions tobring the approximate level of the entire regions to the non-overlappedetching depth in a manner analogous to the way it was done for eveningout deposition differentials.

Of course in alternative approaches, masks with patterns correspondingregions where non-maximal etching occurred or non-maximal depositionoccurred (e.g. double deposition or etching as opposed to quadrupledeposition or etching, and single deposition or etching as opposed toquadruple deposition or etching could be used to cause additionaldeposition or etching such that the amount deposited throughout theregion would be equal to the maximum amount deposited or etched. Thisapproach may not provide a saving in time but it may provide a savingsin material consumption.

In still other embodiments, the width of the cells could be made tomatch the width of the regions separating the cells such that uponoffsetting no overlap would occur. In still other embodiments it may bepossible to use masks having effective deposition or etching widths thatare slightly smaller than the offset used between depositions (e.g. theeffective deposition width of a cell of the mask may be slightly lessthan one-half the width of the region to be deposited to by the cell)where it is anticipated that any gaps between the offset depositionregions will be filled in by as a result of the conformable contactmaterial's inability to enter narrow deposition gaps such that materialbecomes deposited in to the gaps

In still other embodiments MOA type masks and MOC type masks may bereplaced with anodeless and cathodeless masks in that the anode andcathode (at least as far as plating or etching operations is concerned)is not located on or within each cell of the mask but instead isseparate from them. Each cell will include a passage that will, underappropriate conditions, allow ion flow between the substrate and ananode or cathode that is remotely positioned (typically within a volumeof electrolyte that is larger than the volume of electrolytes within theprocess pockets). Each cell will include at least one control electrodeor other control element that can be effectively used to allow orinhibit passage of ions to or from the substrate and thus can be used toselectively control which cells allow deposition or etching and whichcells do not.

In the some embodiments of the present invention it is important tounderstand that it may not be necessary to completely eliminatedeposition or etching in regions protected by inactive cells (i.e. cellsthat are not supposed to allow deposition or etching) but instead it mayonly be necessary to create a sufficient deposition or etchingdifferential (e.g. greater then 5 to 1, more preferably greater than 10to 1 and most preferably greater than 20 to 1). If necessary, smallamounts of deposition within inactive cell regions may be removed byperforming a short or gentle etching operation either in a selectivemanner (e.g. material selectively or region selective, or both) or in abulk manner. Etching may occur via either electrochemical etching orchemical etching.

If necessary, small amounts of etching from inactive regions may beneutralized via a planarization operation that removes material suchthat voids created by undesired etching are removed and thereafteradditional deposition or etch steps can be continued. The planarizationoperation may be followed by a cleaning operation that ensuresplanarization debris is removed from the intended etching voids. As analternative to planarization or as a complement thereto, a selectivedeposition operation can be performed using the multi-cell mask where aslight amount of deposition is made to occur within those inactive cellswhere the material that may have been inadvertently etched into is thesame as the material that is being deposited.

In still further alternatives, if control of active and inactive cellsis difficult, multi-cell masks that contain through passages andnon-erodable electrodes may be used in a multi-operation process toperform selective deposition and/or etching. To perform a depositionoperation from a remote source to the substrate, the following twooperations may be performed:

-   -   1. Treating the remote source as an anode and the active cell        electrodes as cathodes and proceeding with depositing material        from the remote source on to the active cell electrodes. During        this part of the operation the substrate would be left at a        floating potential. The inactive cells may also be at a floating        potential or at a potential equal to or greater than that of the        remote source. During this process, it is preferred that the        cell electrode within the inactive cell remain free of any        deposition material.    -   2. Removing the potential from the remote source and letting it        float or alternatively removing the remote source from the        electrolyte. Treating the active cell electrodes as anodes and        treating the substrate as a cathode. Allowing deposition to        occur. During this operation the potential on the electrodes in        the inactive cells is preferably the same as or greater than the        potential on the active cells. Depending on the flow        restrictions it may be possible for the potential on the        inactive cells to remain floating. A flow restriction that would        allow such a floating potential to be used may involve a second        non-erodable electrode in each cell positioned to be further        away from the substrate than the electrode that is actively        involved in the operations. The potential on this second        electrode would be higher than that on the other cell electrode        such that it provides a barrier to positive ions leaving the        cell. In a further alternative, the second electrode may be        coated with a thin dielectric such that it cannot not        participate in charge transfer while still allowing it to        participate in forming an electrostatic barrier. As necessary,        the mask may be shifted to ensure deposition to all appropriate        locations.

To perform an etching operation from the substrate to a remote materialdepository, two operations analogous to those set forth above may beused. For example, two such operations might include:

1. Treating the substrate as an anode and the active cell electrodes ascathodes and proceed with etching material from the substrate anddepositing it on to the active cell electrodes. During this part of theoperation the remote depository is left at a floating potential or evenremoved from the bath of electrolyte. The inactive cells are held at thesubstrate potential or somewhat higher and they are preferably free ofany erodable material. In an alternative embodiment the cell electrodesin the inactive cells are allowed to float but a second set of possiblyinsulated electrodes in the inactive cells may be set at a potentialequal to or greater than that of the substrate. As necessary the maskmay be shifted relative to the substrate to ensure etching of allappropriate locations.

2. Removing the potential from the substrate and letting it float.Treating the active cell electrodes as anodes and treating the remotedepository as a cathode. Allowing deposition from the active cellelectrodes to the depository to occur. The inactive cell electrodes maybe left floating or may be powered at the same potential as the activecell electrodes.

FIG. 6(a)-6(b) depict a top view and a side view, respectively, of ananodeless multi-cell mask 202 that may be used for deposition to oretching from a substrate 204. The mask consists of a grid 206 of adielectric material 214 having a surface that is to contact or belocated in proximity to a substrate 204. The dielectric material alsosupports cell electrodes 212(1,1) to 212(4,3) which form rings aroundpockets 222(1,1) to 222(4,3) and which have passages 224(1,1) to224(4,3) that allow ion transfer from the substrate 214 to a regionoutside the mask 202.

When used herein, located “in proximity to” or being “proximate to” whenreferring to relative locations of a mask and a substrate shall beconstrued to mean close enough spaced such that deposition or etchingfrom one cell has minimal, or certainly no more than an acceptableamount of deposition to or etching from the regions associated withneighboring cells. If etching operations, or planarization operationsare used to minimize the effects of undesired deposits or voids createdby etching of undesired regions, the extent of what is considered to beacceptable amounts of peripheral deposition or etching may be increased.

In alternative embodiments a rigid dielectric material may be used tosupport the cell electrodes while more conformable or even anelastomeric dielectric may be used for contacting the substrate. Infurther alternative embodiments, the cells may include more than oneelectrode wherein one or more of the electrodes are insulated by adielectric material (e.g. a thin coating of dielectric). In stillfurther alternative embodiments, the cell electrodes can have appendagesand or crisscross grids of elements that extend into or even completelyacross the passages 224. The appendages or electrode grids may beexposed to electrolyte and thus be able to directly receive and or giveup material or they may be coated with dielectrics. In still furtheralternative embodiments some or all of the cell electrodes may take theform of porous conductive structures 212′(1,2)-212′(4,2) as shown inFIG. 7(c). In still further embodiments, the cell electrodes need not belocated at an end of the passages.

FIG. 7 depicts a schematic representation of a plating system that usesa multi-cell mask 302 which is similar to the mask of FIG. 6(b) butshown as have 6 cells. The mask 302 is immersed in an electrolyte 308and is shown has having ends of dielectric 314 contacting a substrate304 along a surface 306. The multi-cell mask includes individual ringlike cell electrodes 312(1)-312(6). The substrate 304 is connected to ananode 318 via a source of electric activation EA. EA is a source ofelectric power (e.g. a substantially constant current source). Whetherelement 318 represents a source of ions or a depository for ions dependson the polarity of the potential supplied by EA. If EA is more positiveon element 318 (anode), then deposition to the substrate 304 (cathode)will occur while if the potential is more positive on the substrate 304(functioning as an anode) then etching of the substrate will occur anddeposition to element 318 will occur.

References V1-V6 indicate that each cell electrode may take anindependent potentials or at least potentials that are selected betweentwo or more values. The potential selected for each cell electrodedetermines whether the cell is active (allows deposition or etching) oris inactive (inhibits deposition or etching). EA and Vi may be looked atin different ways: (1) fixed voltages or voltage differentials or (2)simply as potentials that give current flow a particular direction andwhose magnitude is only relevant relative to other elements in theelectric path.

For deposition (e.g. electroplating) to occur onto the substrate forselected cells, the ion source will function as an anode (+potential)and the substrate will act as a cathode (− potential). Active cells(i.e. the cells that allow deposition) may be allowed to have floatingpotential (i.e. no potential that is fixedly maintained) though in someembodiments they may be given a potential somewhere in between that ofthe anode and that of the cathode. The inactive cells (i.e. the cellswhich will inhibit plating) preferably have a potential at least aslarge as that of the ion source and maybe even somewhat higher. Sincethe cell electrode for the inactive cells presents a higher potentialthan the ion source, ions will be inhibited from entering the cells.Thus significant plating on the portion of the substrate bounded by thecell is inhibited. Preferably the cell electrodes are of a non-erodablematerial such as platinum or silicon but an erodable material may beacceptable if the potential differences are such that significanterosion doesn't occur or current densities are such that significantplating onto the substrate doesn't occur. In some alternativeembodiments where the cell electrodes are used solely for creatingappropriate electrical potentials (as in the present embodiment) and donot participate in current carrying functions of the system, the cellelectrodes may be isolated from the electrolyte (e.g. plating solution)by a dielectric material.

For electrochemical etching, element 318, the depository, functions as acathode (−potential) while the substrate functions as an anode(+potential). The active cell electrodes preferably have floatingpotentials though in some embodiments it may be possible to set theirpotentials at something intermediate to the cathode and anodepotentials. Inactive cell electrodes preferably have a potential asgreat as that of the substrate or more preferably somewhat greater.

In plating embodiments, the space within the cells is filled anelectrolyte that includes a plating solution 322 that extends from thecathode (i.e. substrate) to the anode (i.e. the ion source). In etchingembodiments, the cells are filled with an electrolyte that may alsofunction as a plating solution. In some embodiments the same mask andplating solution may be used for both plating and etching operations byreversing the polarities of the various electrodes.

The system of FIG. 7 may be used in a manner as described above, in amanner described elsewhere herein, or in a manner that will be apparentfrom the teachings herein to those of skill in the art. Furthermore, theimplementation details may be varied and optimized via use of ordinaryskill.

As plating with the masks discussed above may result in some depositioninto the inactive cells it is probable that after selective depositionan electrochemical bulk or selective etch (e.g. via the same multi-cellmask) could be performed for a limited time to remove any unwanteddeposits while not significantly damaging the original depositions. Abulk or selective chemical etch could also be performed.

In the case of bulk etching for cleaning up of unwanted depositions, theoriginal selective deposition data could be modified to accommodate forany XY shrinkage of the selectively deposited material.

FIGS. 5(a)-5(f) illustrate the use of a smart mask having a squarepattern of subanodes lined up in rows and columns while FIGS. 6(a)-6(c)and FIG. 7 illustrate a mask with passages and effective depositionregions in the form of squares lined up in rows and columns. In otherembodiments, other smart mask opening and deposition patterns arepossible.

FIG. 8(a) also depicts a bottom view of one cell of a single cell maskor of a multi-cell mask illustrating an effective deposition region 402associated with the cell, the portion of the dielectric material 404(e.g. conformable material) associated with the cell material, andregion boundary 406 illustrating the size of the region that should beeffectively covered by the cell when part of a multi-cell maskperforming deposition or etching operations. FIG. 8(a) depicts a numberof dimensions associated with the region of the cell: (1) EDWx is theEffective Deposition Width of the cell along an X axis, (2) NRWx is theNominal Region Width along the X axis; (3) HWx is the Half-width of thedielectric along the X axis on each side of the effective depositionregion 402 of the cell; (4) EDWy is the Effective Deposition Width alonga Y axis; (5) NRWy is a Nominal Region Width in Y axis; and (6) HWy isthe Half-width of the dielectric along the Y axis. FIG. 8(b) illustratesa portion of a mask containing four cells 411-414 where the dimensionsof the regions are similar to those depicted in FIG. 8(a). The cells ofFIGS. 8(a) and 8(b) may be used in depositing material in many differentways. Two examples of such deposition patterns are shown in FIG. 9(a)and FIG. 9(b).

FIG. 9(a) illustrates a four step deposition pattern using the four cellmask portion of FIG. 8(b) where each cell is active for each depositionto illustrate that in an embodiment based on this pattern, thedeposition associated with any cell doesn't extend beyond its nominalregion boundary. The region boundary for each of the four cells isillustrated by dotted boundaries 421-424. The initial depositions madeby each of cells 411-414 are illustrated with reference numerals431-434, while the second, third and fourth depositions are illustratedwith numerals 441-444, 451-454, and 461-464. Within the depositionregion for each cell overlapping depositions are shown to have occurredwhere the effective deposition regions overlapped as a result ofsuccessive depositions. In the implementation of FIG. 9(a), theoverlapping depositions only exist within individual boundary regions.This is more clearly illustrated in FIG. 9(b) where a side view alonglines 9 b-9 b of FIG. 9(a) is shown where a larger deposition height isshown in the region of overlap. The depositions of FIG. 9(a) may beachieved via the four step offset pattern set forth in TABLE 1. TABLE 1Depositions Offset to Next Deposition 431-434 +2 * HWx 441-444 +2 * HWy451-454 −2 * HWx 461-464 −2 * HWy (e.g. in preparation for depositionsfor 431-434 for a next layer or a next pass on the present layer)

In other words, if the X and Y half widths are equal, then the offsetsbetween depositions are +/−2*HW (i.e. or plus or minus the width of thedielectric between cell openings, W=Wx=Wy) along one or both of theaxes. To achieve the same deposition pattern these offsets may be takenany order and even combined. Besides changing the order of depositionsand thus changing the offsetting pattern, other offset patterns may beused. For example, similar deposition patterns may be obtained by usingdifferent cells to deposit to the different parts of a given region.Such a mixed cell deposition pattern may be obtained by shifting cellsalong one or both axes by one or more region widths (2*HWx+EDWx in X or2*HWy+EDWy in Y) and adding or subtracting the dielectric width (2*HWxin X or 0.2*HWy). In other words, the offsets may beN*(2*HWx+EDWx)+/−2*HWx in Xand/orN*(2*HWy+EDWy)+/−2*HWy in Y.

FIG. 9(c) depicts a second example of a deposition pattern that might beachieved using offsets to ensure the potential for deposition to allportions of all regions. The resulting depositions, according to thispattern, include not just intraregion overlaps but also interregionoverlaps. In this example where all masks are used at each depositlocation, each deposition is overlapped on its edges by neighboringdepositions. The first deposition of the pattern deposits regions501-504, the second deposition deposits regions 511-514, the thirddeposition deposits regions 521-524, and the fourth deposition depositsregions 531-534. The overlapped edge depositions are shown under theassumption that such depositions would have been made by additionalcells that would form part of the mask. As can be seen, a portion of thedeposits associated with one cell overlay the region associated with aneighboring cell (e.g. deposits 511 and 521 from cell 411 overlay aportion of the region associated with cell 412 and similarly a portionof the deposits for 502 and 532 overlay the region associated with cell411. This type of deposition pattern provides less intra-region overlapby providing some intra-cell overlap. This technique results in a lossof resolution (related to the amount of inter-region overlap but mayensure better region to region mating. As with the excess depositionsassociated with FIG. 9(a), the excess deposition of material associatedin FIG. 9(c) may be trimmed away by a planarization operation (e.g.lapping).

FIG. 9(d) depicts a side view of the depositions along lines 9(d)-9(d)of FIG. 9(c). These lines show a larger deposition height in the regionof overlap and that the overlap is narrower than that shown in FIG.9(b). In this example the offsets between successive depositions maytake the form indicated in TABLE 2. TABLE 2 Depositions Offset to NextDeposition 501-504 +2 * [½ * (½ EDWx + HWx] = ½ * EDWx + HWx 511-514+½ * EDWy + HWy 521-524 −(½ * EDWx + HWx) 531-534 −(½ * EDWy + HWy)

In other embodiments, other offsets may be used while still achievingboth intra-cell and inter-cell overlap. For example, individual cellsmay be used in depositing material to other cell regions by adding to orsubtracting from the increments set forth above by an integral number ofwidths of the entire region (i.e. “EDWx+2*HWx” along the X axis or“EDWy+2*Hwy” along the Y axis).

FIGS. 10(a)-10(c) depict a third example of a deposition pattern. Insome embodiments the deposition pattern of FIGS. 10(b)-10(c) may bepreferred in that less deposition overlap occurs and it may be possibleto spend less time trimming down the deposit. It may also be preferredin that it offers enhanced resolution for a given sized EffectiveDeposition Width (EDW) for each cell. FIG. 10(a) depicts the regionassociated with a single cell of a multi-cell mask. In this example, theeffective deposition width (EDWx and EDWy) are equal to twice therespective half-widths of the dielectric material (i.e. 2*HWx and 2*HWy,respectively). In this example, the offsets are selected such thatadjacent deposits contact one another but do not overlap. Depositionbegins with each of the four cells depositing material to theirrespective locations so that deposits 551-554 are made. The mask is thenoffset and depositions 561-564 are made. The mask is offset again anddepositions 571-574 are made. Another offset is performed and deposits581-584 are made. Additional offsets and depositions may be made if itis desired to build up deposition height).

FIG. 10(c) depicts a side view of deposits 551, 561, 552 and 562 alonglines 10 c of FIG. 10(b).

In practice, this type of non-overlapping deposition pattern may be usedwhere the resolution is defined as being related to the region size orto the EDW for each cell. If the resolution is to be related to theregion size, then during deposition individual cells may receive anactive or inactive command that would apply to each deposition in thepattern, whereas if the EDW is to dictate the resolution the active orinactive status of each cell would need to be updated for eachdeposition operation depending on whether the next deposition locationis receive a deposit or not.

Other non-overlapping deposition embodiments are possible where thenominal region width (NRW) is an integral multiple of the EDW. Theseother embodiments may use more than two depositions locations for eachcell along the X and/or the Y axes such that the number of depositionsto complete a layer increases beyond 4 (e.g. 6 for a 3×2 region, or 9for a 3×3 region).

Still other non-overlapping deposition embodiments may use an NRW thatis somewhat larger than an integral multiple of the EDW. Embodiments ofthis type might be more preferable in some circumstances as they may beable to avoid unintended overlaps in deposits that might result fromtolerances in EDW or NRW sizing or tolerances in positioning resolution.If the widths of the openings in the mask are just slightly smaller thanthe width of the dielectric material that separates the openings, it isbelieved imperfect conformability of the dielectric will inhibit thedielectric from completely closing the small gap between a region to bedeposited. This inability to completely close the gap will result in theprevious and current depositions contacting one another. This isillustrated in FIGS. 11(a)-11(g).

FIG. 11(a) depicts a side view of the partially conformable contactmaterial 602(a)-602(c) of a mask contacting a substrate 604 where theconformable contact material defines two cells 608(a) and 608(b). FIG.11(b) depicts the mask being used in making a first deposit 612(a) and612(b) of material 614 onto the substrate. FIG. 11 (c) depicts the maskbeing lifted from the substrate and the deposit while FIG. 11(d) depictsthe mask being shifted to the right relative to the substrate anddeposit. FIG. 11(e) depicts the contact material 602(a) and 602(b)pressed against deposit 612(a) and 612(b) respectively, and contactmaterial 602(c) pressed against substrate 604. FIG. 11(f) depicts thedepositions 616(a) and 616(b) that occur when the mask and substrate arepressed together in the indicated positions. FIG. 11(g) depicts theresulting depositions after removal of the mask. As can be seen thedeposit includes indentations 618(a)-618(c) where the conformablematerial extended beyond the first depositions 612(a) and 612(b) andextended into the regions to receive depositions 616(a) and 616(b). Ifdesired, these indentations may be removed by planarizing the surface ofdeposits and as such any negative impact associated with the formationof such indentations can be eliminated by making the initial deposits alittle thicker than desired for the final layer thickness.

As noted elsewhere herein, in other embodiments, the shape of the cellsmay take other forms and/or the pattern of the cells may take otherforms. Examples of such shapes and patterns are illustrated in FIGS.12(a)-12(d). FIGS. 12(a) and 12(b) depict patterns where circular cellconfigurations 626 and 628 (i.e. effective deposition areas) are formedwithin the dielectric materials 622 and 624, respectively. In FIG. 12(a)the circular cell configurations are laid out in a rectangular gridwhile in FIG. 12(b) they are laid out in a hexagonal pattern. Theseconfigurations may require use of higher numbers of shifting anddeposition operations but they can result in final deposition patternswith potentially less “pixel-to-pixel” discontinuity (i.e. they canresult in less of a horizontal stair stepping effect). Rectangular orsquare cell configurations can also result in smaller stair steppatterns if they are made smaller or if smaller shifting steps are usedin combination with more and perhaps shallower deposition operations.

FIG. 12(c) depicts hexagonal shaped cell configurations 632 separated byrelatively narrow dielectric boundary regions 634 which is supported bya base 636. With this pattern of subanodes a three-step deposition andoffsetting pattern may be used to achieve complete deposition as will bediscussed herein latter.

FIG. 12(d) illustrates a top view of an up-facing rectangular grid ofsquare cell configurations with each having a width “A” and with eachspaced from one another by a width “B” wherein the widths “A” and “B”are substantially equal or where “B” is slightly larger than “A” as wasthe case in FIGS. 10(a)-(c) and 11(a)-(g). However, in this embodimentthe contacting dielectric material 642 (i.e. the dielectric that cancontact the substrate) does not extend completely between the cellopenings 644 but instead forms isolated square rings around theindividual cell openings with a gap between each ring in which arecessed dielectric 646 is located. A side view of the mask along lines12(e)-12(e) of FIG. 12(d) is shown in FIG. 12(e) in which individualelectrodes 648 can be seen to be located within the individual cellopenings and which are supported by a base 650. In FIG. 12(e), theelectric connections for the individual electrodes are not shown. Thegaps 652 between the dielectrics 642 around each cell opening mayprovide more independent sealing when contract between the mask and asubstrate is made.

FIG. 12(f) depicts a top view of an alternative type of multi-cell maskwhere multiple cells configurations are provided. In this example,square cells and circular cells are provided. The square cells may benormally used while the circular cells could be used for regions where aparticularly smooth transition is required or desired.

FIG. 13(a) depicts an alternative mask configuration 702 based onhexagonal openings 704(a)-704(m) that are spaced from one another by aregion of dielectric material that has a configuration made up ofhexagonal shapes 706. This pattern of openings and dielectric may beused to form selective patterns of deposition in a three step set ofdeposition and shifting operations as illustrated in FIGS. 13(b)-13(d).FIG. 13(b) depicts a top view of the deposition pattern that resultsfrom using the mask pattern of FIG. 13(a) where all cells but thoseassociated with openings 704(k) and 704(d) are active. The cellsassociated with openings 704(k) and 704(d) are not active in thisexample as the pattern to be deposited doesn't require depositions fromthese cells during this first deposition position. FIG. 13(c) shows theresult of the first and second depositions with the second depositionoffset from the location of the first deposition where all of the cellsexcept those associated with openings 704(m) and 704(g) are active. Aswith FIG. 13(b) the outline of the regions not deposited to by theinactive cells are shown but without any filling pattern. FIG. 13(d)shows the result of the first through third depositions with the thirddeposition offset from the locations of both the first and seconddepositions. During the third deposition all of the cells except thoseassociated with openings 704(n) and 704(g) are active. As with FIGS.13(b) and 13(c), the outline of the regions not deposited to by theinactive cells are shown but without any filling pattern. FIG. 13(e)illustrates the net result of the three depositions without anyindication of the locations of the non-deposition positions. As can beseen, a three step deposition pattern can be used to fill the entireregion. Other patterns of selective deposition could be obtained usingthis embodiment by selectively controlling the activities of the cellsassociated with openings 704(a)-704(n) during the series of depositions.

FIG. 14(a) depicts an alternative mask configuration 712 based on squareopenings 714(a)-714(i) that are spaced from one another by a region ofdielectric material that has a configuration made up of square shapes706. The configuration of these openings is such that the spacingbetween openings within a column is equivalent to twice the openingheight while the openings within adjacent columns are located in linewith the midpoint of the dielectric in the adjacent columns. Thisconfiguration allows the formation of straight lines in lines parallelto the columns (i.e. the y-direction) but not along lines in theperpendicular direction (i.e. the x-direction). This pattern of openingsand dielectric may be used to form selective patterns of deposition in athree step deposition and shifting set of operations as illustrated inFIGS. 14(b)-14(d). FIG. 14(b) depicts a top view of the depositionpattern that results from using the mask pattern of FIG. 14(a) where allcells but those associated with openings 714(h) and 714(i) are active.The cells associated with openings 714(h) and 714(i) are not active inthis example as the pattern to be deposited doesn't require depositionsfrom these cells during this first deposition position. FIG. 14(c) showsthe result of the first and second depositions with the seconddeposition offset from the location of the first deposition where all ofthe cells except those associated with openings 714(a)-714(c) areactive. As with FIG. 14(b) the outline of the regions not deposited toby the inactive cells are shown but without any filling pattern. FIG.14(d) shows the result of the first through third depositions with thethird deposition offset from the locations of both the first and seconddepositions. During the third deposition all of the cells except thoseassociated with openings 714(a)-714(c) are active. As with FIGS. 14(b)and 14(c), the outline of the regions not deposited to by the inactivecells are shown but without any filling pattern. FIG. 14(e) illustratesthe net result of the three depositions without any indication of thelocations of the non-deposition positions. As can be seen, a three stepdeposition pattern can be used to fill the entire region. Other patternsof selective deposition could be obtained using this embodiment byselectively controlling the activities of the cells associated withopenings 714(a)-714(i) during the series of depositions.

FIG. 15(a) depicts an alternative mask configuration 722 based onhexagonal openings 724(a)-724(n) that are spaced from one another by aregion of dielectric material that has a configuration made up oftriangle-like structures having their vertices truncated into short linesegments. The configuration of these openings is such that the spacingbetween openings is smaller than the width of the openings along thethree axes of the hexagon patterns that form the openings. Theoffsetting of the openings during successive depositions can occur insuch a way that overlaps between the deposition's patterns can occur. Insome alternatives the overlap may be symmetric while in otherembodiments it may not be symmetric. This pattern of openings anddielectric may be used to form selective patterns of deposition in athree step deposition and shifting set of operations as illustrated inFIGS. 15(a)-15(d). FIG. 15(b) depicts a top view of the depositionpattern that results from using the mask pattern of FIG. 15(a) where allcells but those associated with openings 724(d) and 724(k) are active.The cells associated with openings 724(d) and 724(k) are not active inthis example as the pattern to be deposited doesn't require depositionsfrom these cells during this first deposition operation. FIG. 15(c)shows the result of the first and second depositions with the seconddeposition offset from the location of the first deposition where all ofthe cells except those associated with openings 724(g) and 724(n) areactive. As with FIG. 15(b) the outline of the regions not deposited toby the inactive cells are shown but without any filling pattern. FIG.15(d) shows the result of the first through third depositions with thethird deposition offset from the locations of both the first and seconddepositions. During the third deposition all of the cells except thoseassociated with openings 724(g) and 724(n) are active. As with FIGS.15(b) and 15(c), the outline of the regions not deposited to by theinactive cells are shown but without any filling pattern. FIG. 15(e)illustrates the net result of the three depositions without anyindication of the locations of the non-deposition positions. As can beseen, a three step deposition pattern can be used to fill the entireregion. Other patterns of selective deposition could be obtained usingthis embodiment by selectively controlling the activities of the cellsassociated with openings 704(a)-704(n) during the series of depositions.

FIGS. 16(a) and 16(b) depict two alternative mask configurations 732 and742 that include complementary triangular shaped openings 734(a)-734(r)and 744(a)-744(r), respectively, that define the effective depositionregions of their respective cells. Each opening takes a triangle formwith the openings separated from other openings by triangular shapedsections 736 and 746, respectively, of dielectric material that are ofthe same size or slightly larger than the size of the openings. The maskof FIG. 16(b) may be a different mask from that depicted in FIG. 16(a)or it may simply be a rotated version of what is in FIG. 16(a). Thispattern of openings and dielectric may be used to form selectivepatterns of deposition in a two step deposition and shifting set ofoperations as illustrated in FIGS. 16(c)-16(d). FIG. 16(c) depicts a topview of the deposition pattern that results from using the mask patternof FIG. 16(a) where all cells actively participate in the deposition.FIG. 16(d) shows the result of the first and second depositions with thesecond deposition based on the mask of FIG. 16(b) and with the openingspositioned over the dielectric locations from the first depositionoperation. Other patterns of selective deposition could be obtainedusing this embodiment by selectively controlling the activities of thecells associated with openings 734(a)-734(r) and 744(a)-744(r) duringthe series of depositions.

Another example of a two step embodiment is illustrated with the aid ofFIGS. 17(a)-17(d). FIG. 17(a) depicts an alternative mask configuration752 that includes square openings 754(a)-754(l) located in acheckerboard pattern. Since the openings are located in a checkerboardpattern, the dielectric material that separates the openings is in acomplementary checkerboard pattern. This pattern of openings anddielectric may be used to form selective patterns of deposition in a twostep deposition and shifting set of operations as illustrated in FIGS.17(b) and 17(c). FIG. 17(b) depicts a top view of the deposition patternthat results from using the mask pattern of FIG. 17(a) where all cellsexcept for those associated with openings 754(k) and 754(l) activelyparticipate in the deposition. The non-participation of these cells isshown by the two lower square outlines that do not contain any filingFIG. 17(c) shows the result of the first and second depositions with thesecond deposition offset from the first deposition by the openings beingpositioned over the dielectric locations from the first depositionoperation. Openings 754(a) and 754(b) do not participate in the seconddeposition as indicated by the outlined squares without filing as shownat the top of FIG. 17(c). FIG. 17(d) illustrates the net result of thetwo depositions without any indication of the locations of thenon-deposition positions. Other patterns of selective deposition couldbe obtained using this embodiment by selectively controlling theactivities of the cells associated with openings 754(a)-754(l) duringthe series of depositions.

In alternative embodiments to those illustrated in FIGS. 16(a)-16(d) and17(a)-17(d), other opening patterns could be used. In otheralternatives, the dielectric material separating the individual cellsmay be truncated where they meet at their corners such that a small gapexists that connects each cell. It is believed that this gap may notallow significant deposition from active cells to enter inactive cellsbut if such unwanted deposition occurs on a limited basis, it may bepossible to perform an etching operation to remove the unwanted materialwithout significantly distorting the desired deposition pattern.

As discussed herein above, in some embodiments due to the presence ofoverlapped depositions, non-uniformity of deposition height may beproblematic. In some embodiments, this problem may be addressed by useof planarization operations to smooth the deposits. In otherembodiments, selective etching may be used to enhance the uniformity ofthe deposition. An example of this type of technique is illustrated withthe aid of the deposition pattern of FIG. 8(a). A region associated witheach cell receives deposits from a series of four depositions andoffsets as indicated in FIGS. 18(a)-18(d). First through fourthdepositions occur at positions 802(a)-802(d), respectively, which areindependently shown in relationship to the overall deposition region 804that is controlled by a particular cell. The successive depositionschange the net deposition pattern for the region. The resulting heightof deposition after each of the four deposits is illustrated with theaid of FIGS. 19(a)-19(d), respectively.

After the first deposition, as shown in FIG. 19(a), the area 802(a) hasa deposition height of one unit while the rest of region 804 has a zerodeposition height.

FIG. 19(b) shows that region 804 contains four distinct depositionregions after completion of the second deposition: (1) a region 812(a)deposited to by only the 802(a) deposition and having a height of oneunit; (2) a region 812(b) deposited to by only the 802(b) deposition andhaving a height of one unit; (3) a region 812(ab) deposited to by boththe 802(a) and 802(b) depositions and having a height of two units; and(4) a remaining portion of region 804 that has yet to receive a deposit.

FIG. 19(c) shows that region 804 contains seven distinct depositionregions after completion of the third deposition: (1) a region 812 adeposited to by only the 802(a) deposition and having a height of oneunit; (2) a region 822(b) deposited to by only the 802(b) deposition andhaving a height of one unit; (3) a region 822(ab) deposited to by boththe 802(a) and 802(b) depositions and having a height of two units; (4)a region 822(bc) deposited to by both the 802(b) and 802(c) depositionsand having a height of two units; (5) a region 822(abc) deposited to byeach of the 802(a), 802(b), and 802(c) depositions and having a heightof three units; (6) a region 822(c) deposited to by only the 802(c)deposition and having a height of one unit; and (7) the remainingportion of region 804 that has yet to receive a deposit.

FIG. 19(c) shows that region 804 contains nine distinct depositionregions after completion of the third deposition: (1) a region 832 adeposited to by only the 802(a) deposition and having a height of oneunit; (2) a region 822(b) deposited to by only the 802(b) deposition andhaving a height of one unit; (3) a region 822(ab) deposited to by boththe 802(a) and 802(b) depositions and having a height of two units; (4)a region 822(bc) deposited to by both the 802(b) and 802(c) depositionsand having a height of two units; (5) a region 832(abcd) deposited to byeach of the 802(a), 802(b), 802(c), and 802(d) depositions and having aheight of four units; (6) a region 832(c) deposited to by only the802(c) deposition and having a height of one unit; (7) a region 832(cd)deposited to by both the 802(c) and 802(d) depositions and having aheight of two units; (8) a region 832(d) deposited to by only the 802(d)deposition and having a height of one unit; and (9) a region 832(ad)deposited to by both the 802(a) and 802(d) depositions and having aheight of two depositions.

Ignoring possible flash related depositions that might occur as a resultof imperfect mating between the mask and the substrate (especially inthose regions that transition from one deposition height to another) andassuming that all four depositions that are within the region are usedto deposit material, the four step pattern doesn't yield a uniformdeposition depth but instead some portions of the region receive asingle unit of deposition height, some receive two units of depositionheight, and some receive four units of deposition height. A unit ofdeposition may be any height which is assumed to be the same for eachdeposition operation in this example but need not be in otherembodiments. If the entire layer thickness is to be achieved by thesefour depositions, the height of deposit may be equal to that of thelayer thickness or may be somewhat larger. If instead, multiplerepetitions of this four step process are to occur, then the height ofone unit may be a fraction of the layer thickness.

A potential problem with the resulting deposition pattern is that itdoesn't have anything approaching a uniform deposition depth. In thisexample, the height of the deposition will vary by a factor of four.This may be non-problematic in some circumstances (e.g. whenplanarization will be used to bring the height of deposition down to adesired level, such as to the one unit height assuming the cost ofdeposition material, deposition time, planarization time, and the likeare not too high).

As discussed above, an implementation of a deposition height or etchingdepth differential reduction technique may involve performing thereverse of a portion of the deposition or etching using specially shapedcells in a multi cell instant mask. As also discussed above, otheralternatives may add to the results of a deposition or etching byadditional deposition or etching using specially shaped cells.

One additional mask and etching operation may be used to bring thedeposit differential down from 4:1 to 2:1. This extra mask could be usedin a single etching operation to reduce all of the “4” unit depositionsdown to a lower level (e.g. a two unit level or even a one unit level).FIG. 20 illustrates a cell pattern that each cell of a supplementalmulti-cell mask might possess for use in reducing the overall heightdifferential. FIG. 21 illustrates multi-cells of a mask that includesopenings like that of FIG. 19 arranged in a square array. FIG. 22depicts a sample pattern that might be deposited by 6 cells C1-C6 of amulti-cell mask where each active cell (e.g. cells 1, 2, 5, and 6)deposits the pattern of FIG. 18(d) while FIG. 23 depicts the resultingnet deposit after a single etching operation using the mask of FIG. 21with active cells corresponding to those that were active during thedeposition operations. Of course the resulting height of the originalfour units may take on any value but in this example, it has beenassumed they would be reduced to a two unit height.

If it were desired to bring the net deposition differential down evenfurther, a desired mask pattern could be used to etch the portions ofthe deposit that are thicker down to match the height of the thinnerdeposit (e.g. etch the two unit height down to a height of about oneunit). Alternatively, additional material may be deposited (e.g. using amask having cells with an appropriate pattern) to the thinner portion ofthe deposition to bring it closer to the height of the thicker portionof the deposit (e.g. to bring the height of the one unit thick portionto about the height of the two unit portion). The additional etchingoperations may involve 2 or more offsets with specially configuredcells.

For example the mask of FIG. 24(a) may be used to etch down the two unitthick portion in two offset etching operations while the mask of FIG.24(b) may be used to etch the two unit thick portion in four offsetetching operations.

Though the above approach of depositing extra material and thenselectively etching away the excess material achieves the desiredresult, it may not be as time efficient as an approach that depositsmaterial so that the overlapped portions (e.g. the portions that receivemultiple deposits) reach the desired height while the non-overlappedportions are subsequently filled in using one or more masks of desiredconfiguration.

As discussed elsewhere herein, some embodiments may use bubble formationto control the activity of individual cells of a multi-cell mask. In anembodiment that doesn't contact the masks against the substrate duringdeposition, it is possible that multi-step plating will not benecessary. In other words, a single position of the cells may be able toplate all appropriate portions of the substrate. If the bubbles seal thecells and possibly partially locate themselves under the cell dielectricboundaries, three unique situations can occur at cell boundary lines:(1) Off-cell meets off-cell—no depositions within cells and nodepositions under cell dividers; (2) Off-cell meets on-cell—depositionin on-cell—no deposition in off-cell—extent of deposition under celldividers depends on the extent the bubbles are located under thedividers; and (3) On-cell meets on-cell—depositions in thecells—deposition under the dividers (height of deposition is limited tothat of the spacing between the dividers and the substrate).

Variations of these three situations can occur. In particular the finaldeposition position and boundary shape in situation (2) can impact theaccuracy of the final structure and the surface finish of a series ofstacked layers. In situation (3) if the divider is too close to thesubstrate the entire region under the divider may not fill in prior tothe deposit on each side sealing against the divider.

It is believed that in some embodiments it may be possible to performthe mask and substrate set up, cell activation (and/or deactivation),and the deposition operations such that entire layers may be formedusing single depositions. It is also believed that the process may beperformed such that the position of boundary lines between depositionand non-deposition zones may be sufficiently predictable that theoriginal structure/object/device data may be modified to enhance theaccuracy of the final produced structure. It may also be possible totailor the process, mask cell divider shape, etc. so that boundary shapeis also optimized.

An example of a mask and two sample depositions are shown in FIGS.25-29. FIG. 25 illustrates a mask 852 that includes three cells854(a)-854(c). The mask also includes dielectric extensions856(a)-856(d) that separate the cells from one another and each cellincludes control elements 858(a 1) and 858(a 2), 858(b 1) and 858(b 2),and 858(c 1) and 858(c 2), respectively. The control elements may bebubble generation electrodes that may be formed from a non-erodablematerial through which a current can pass to hydrolyze a portion of anaqueous plating bath with minimal material transfer between theelectrodes. The cells may be of the pass through-type (anodeless-type)or they may include erodable anodes 860(a)-860(c), respectively, thatcan give up material during deposition operations. The mask ispositioned relative to a substrate 862 and a controlled current source864 is connected between the anodes 860(a)-860(c) and the substrate forpowering the deposition of material once the activation/deactivation ofeach cell is set. An electrolyte (e.g. a plating solution) is locatedwithin the cells between the control elements and between the anodes andthe substrate. The control elements for the cells may be connected viaindependent lines to controllers 866(a)-866(c) or they may be connectedto a controller or to a reduced set of controllers via wiring andcircuitry for multiplexed control. In the case of the control elementsbeing hydrolysis electrodes they may be powered by either a DC voltageor an AC voltage which might help limit any material deposition to theelectrodes.

FIG. 26 depicts the mask of FIG. 25 where cells 854(a) and 854(b) areshown as deactivated by the formation of bubbles 868(a) and 868(b) whilecell 854(b) is not blocked by a bubble and thus remains active such thatdeposition 872(c) may be formed. As can be seen the formation of bubbles868(a) and 868(b) partially extend under dielectric dividers856(a)-856(c) such that the boundary between deposition regions andnon-deposition regions is set as indicated by boundary 874(bc).

FIG. 27 depicts the deposition of FIG. 26 after the mask has been movedaway from the substrate.

FIG. 28 depicts the depicts the mask of FIG. 25 where cell 854(a) isdeactivated by the formation of bubble 868(a) while cells 854(b) and854(c) remain active such that deposition the combined deposition 872(b)and 872(c) may be formed. As can be seen the formation of bubbles 868(a)partially extends under dielectric dividers 856(a)-856(b) such that theboundary between deposition regions and non-deposition regions is set asindicated by boundary 874(ab).

FIG. 29 depicts the deposition of FIG. 28 after the mask has been movedaway from the substrate.

From FIGS. 26-29 it is clear that the embodiment appropriately handlesthe interface between “on-on” cells, “off-off” cells, and “on-off” cellswith a single deposition without need for horizontal shifting.

In alternative embodiments many features of the embodiment of FIGS.25-29 are possible. For example, the width of the dielectric dividersrelative to the width of the cells may be different. The separationbetween cell dividers and the substrate may be different. It ispreferably at least one layer thickness and possibly a bit more so thata deposition thickness between the dividers and the substrate can be atleast one layer thickness and preferably somewhat more. The shape of thedielectric dividers can vary, for example, by making their lowerextremes have a curved shaped. As in ELEX™ approaches to EFAB, as setforth in U.S. patent application Ser. No. 10/271,574, Oct. 15, 2002 byCohen et al. which is incorporated herein by reference, the separationbetween the mask and substrate may start off small and increase as thedeposits thicken. An analogous process may be possible for selectiveetching possibly with the separation decreasing as etching depthincreases.

In still further alternatives, the bottom surface of the dielectricdividers may contain bubble producers and such masks bubble producersmay allow use of masks where the physical dielectric doesn't extendbelow the cell electrodes and maybe even where the dielectric doesn'tcompletely extend to the bottom of the cell electrodes. This isillustrated in FIG. 30 where cell electrodes 882(a)-882(c) are heldseparate by dielectrics 884(a)-884(d) with bubble generator locatedbetween the dielectrics. In these alternatives the bubble generatorscould create dividers between those cells where necessary to separate“on” sections from “off” sections and individual control of cellactivity could control which cells are powered for deposition and whichare not.

In still other alternatives, the orientation of the mask and substrateof FIG. 25 may be inverted such that gravity may cause the bubbles torise and contact and seal the mask and the substrate without the bubblesfirst needing to fill their entire respective cells.

In still further embodiments, the bubbles may not need to contact thesubstrate. In these alternatives, the sealing between the mask and thesubstrate may be caused by contact between the cell dividers and thesubstrate where the bubbles are simply used as cellinactivators/controllers.

In still other alternative embodiments, the spacing between thesubstrate and the mask and the divider width may be sufficient to limitdepositions to individual cell regions with or without formation ofbubbles that bridge the space between the mask and the substrate. Anexample of this is illustrated in FIG. 31 where a mask 892 includes fivecells (i.e. deposition electrodes 894(a)-894(e), respectively) separatedby dielectric dividers 896(a)-896(f). In the example, illustrated thedividers do not extend beyond the face of the deposition electrodes andit is assumed that cells 894(c) and 894(d) are not powered fordeposition while the other cells are. A deposit resulting from thisoperation of this mask is indicated by reference numerals 898(a) and898(b) this

In alternatives embodiments, FIGS. 25-31 and their various alternativesmay be used in combination with offsets and extra depositions. This maybe particularly useful if adjacent on-cells are incapable of completelybridging the divider regions either as a result of the dividerscontacting the substrate or by the width of the divider making bridgingimpossible or unreliable.

In still further alternatives, the masks containing anodes may bereplaced by anodeless-type masks. For bubble forming embodiments thisalternative is particularly enabled by the substrate being on top sothat bubbles don't escape from the cells. This alternative may work inthe mask-on-top approach if the passages are bridged by a porousstructure that inhibits the passage of bubbles or where surface tensioneffects reliably hold the bubbles in place.

Other multi-cell programmable mask embodiments may involve varying thecell divider height. The divider height could be made high wheretransitions from active cell regions to inactive cell regions occur suchthat those dividers could seal the mask to the substrate. Dividersseparating active cells from one another or inactive cells from oneanother could be set low so they would not contact the substrate. Inthese embodiments it may be preferable to have the dividers along eachwall of each cell to be capable of independent movement. The dividerheight sets, seals, and separates the active and inactive regions fromeach other as well as allows flow between all connected cells of asingle type. Each cell is still preferably independently controlled fordeposition or no deposition.

The heights of the dividers may be set in various ways. For example, insome embodiments, the height of the dielectric may be set by pushing itagainst an appropriate pattern (e.g. a programmable solenoid orelectrostatically controlled bed of rods) that can set the dielectric toa high or low state. The dielectric may, for example be heated when itis pressed against the bed to place it in a modifiable state so that itsshape may be adjusted. It may be cooled prior to removing it from thebed to lock it into position before removing it from the contouringpattern. This method of setting divider height is illustrated in FIGS.32(a)-32(d). FIG. 32(a) depicts a side view of a mask 902 having threecells 904(a)-904(c) separated by dielectric dividers 906(a)-906(d) wherethe dividers may be formed from a shape memory material (i.e. a materialthat has a nominal shape that can be made to take a modified shape andthen reset to its original shape, for example by heating). FIG. 32(b)shows mask 902 in position for being mated to contour pattern bed 908which includes moveable rods 912(a)-912(d). Rods 912(b) and 912(d) areshown in elevated positions while rods 912(a) and 912(c) are shownrecessed positions. Before bringing the mask and the bed into contactwith one another, the mask, if necessary to take and hold a temporarydeformed shape, may be heated. This heating operation may be used tocause all elements of the dielectric to extend to their normal lengths.The mask and bed are then pressed together as shown in FIG. 32(c) wherethe mask takes on the shape of the bed (if necessary the mask may be ina heated state during the application of pressure). Prior to separatingthe mask and the bed, the mask is cooled (if it were heated duringpressing) to lock it in the modified shape. The deformed mask isillustrated in FIG. 32(d) and is ready for use.

In some alternative embodiments, if the mating properties (e.g.deformability or elasticity) of the selected shape memory material areinappropriate to obtain the desired conformity for sealing the mask andthe substrate, the shape memory material may have a region ofconformable material applied to its surface (e.g. PDMS).

A second embodiment may achieve differential height of the dielectricdivider material by contacting the dividers to a material that willtemporally adhere to them. This material may be selectively applied tothe transitional boundaries to increase their height. After mating anddeposition the temporary material may be removed and a new pattern ofextender material may be applied to the multi-cell mask's transitionaldividers. The extender material may be a material deposited directlyonto the divider or may be a material that is first patterned onto adifferent surface and then transferred to the dividers; The materialmay, for example, be applied by ink (such as a wax-like material). Itmay be a toner that is deposited electrostatically.

An example of a transfer approach is shown in FIGS. 33(a) and 33(b).FIG. 33(a) depicts a mask 922 pressed against a pattern transfer base926. The mask includes dielectric dividers 924(a)-924(d) having uniformlength. The base 926 includes previously deposited features 928(a),928(c) and 928(d). FIG. 33(b) shows the mask 922′ separated from thebase 926′ where the features 928(a), 928(c), and 928(d) have beentransferred to the ends of dielectric dividers 924(a), 924(c), and924(d) to extend their length. The mask 922′ is ready for depositionoperations after which the extension features may be removed.

Another example of a transfer approach is shown in FIGS. 34(a)-34(c).This alternative has some similarities to the FIG. 33(a)-33(b) approachbut instead of transferring material only to the bottoms (or tops) ofthe dividers, a border of material is transferred to the surface of themask where the border may overlay not only the dielectric material butalso the openings of the cells so as to form a boundary betweendeposition regions and non-deposition regions. In some embodiments theboundary material may free the deposition and non-deposition regionsfrom the quantized dimensions of the cells. FIG. 34(a) shows a top viewof the cells of a mask 932 prior to transfer of a boundary material 934.FIG. 34(b) shows a top view of the mask 932′ after transfer of theboundary material 934 while FIG. 34(c) shows a side view of the mask932′ along lines 34(c)-34(c) of FIG. 34(b) where the thickness added bythe boundary material 934 can readily be seen. In some embodiments, theborder may be formed on a separate surface and then transferred to theselected dividers/cells of the mask or alternatively it may be formeddirectly onto the multi-cell mask. The pattern may for example be formedvia inkjet deposition or an extrusion technique such as fused depositionmodeling

In the above differential height embodiments, the created masks are usedto contact the substrate such that the entire region can be patterned bya deposition in a single process; however in other embodiments proximitypositioning of the mask relative to the substrate might allow adequateseparation of the deposition and the non-deposition regions.

In some embodiments cell position may be aligned from layer-to-layerwhile in other embodiments cell positioning may be shifted betweenconsecutive or periodic layers. In still other embodiments, cell sizemay be varied on different layers or even varied within a layer.Embodiments that vary cell alignment positioning or cell sizing mayyield structures with different mechanical properties than similarlyconfigured structures that are produced when cell alignment ismaintained fixed from layer-to-layer. Such formation techniques arecontrasted in FIGS. 35(a)-35(f). FIG. 35(a) depicts a side view of anobject containing a number of layers without explicit indication of thecell boundaries that were used during its formation. FIG. 35(b) depictsa side view of the object of FIG. 35(a) which is formed from amulti-cell mask where cell size is fixed and cell alignment is fixed(i.e. no offsetting of cells occur) between layers.

FIG. 35(c) depicts a side view of an object produced when offsetting isused on consecutive layers. As illustrated, the offsetting or shiftingis from cell edge to cell midpoint on every other layer. In theembodiment of FIG. 35(c) some depositions appear to have half the widthof other depositions. This apparent deposition size variation may beobtained in two ways: (1) smaller cells may be used in making some edgedeposits while larger sized cells are used to make interior deposits(i.e. deposits that do not have an edge that matches the edge of thelayer) and exterior deposits (i.e. deposits that do have at least oneedge that matches the edge of the layer) when those exterior depositscan be made without loss of layer positioning or size resolution, or (2)the same sized cells may be used for all depositions but exteriordepositions may be made with the cells at shifted positions when theshifting is required to maintain a desired layer size or resolution.

FIG. 35(d) depicts the use of shifted cells on every third layer and theuse of different sized cells or cells with special shifting whenexterior layer features require it.

FIG. 35(e) depicts the use of shifted cells on every other layer incombination with larger cells when needed to form exterior portions oflayers when the larger cells can be effectively used to obtain properlayer sizing.

FIG. 35(f) depicts an embodiment where a different sized cell is used inthe formation of every other layer.

In further embodiments different cell size relationships may be used anddifferent offsetting or shifting parameters may be used. Deposition maynot concern itself with maintaining layer size or feature position withregard to an original design concept but instead may base layer sizeand/or feature position on the desired cell alignment positions andquantization thus associated with each layer. The quantization maydetermine whether or not any given cell position is a depositionposition or not based on some predefined criteria. Examples of suchcriteria include: (1) formation of over-sized structures in that anydata calling for material presence within a given deposition positionmay dictate that the deposition is to occur, (2) formation of undersizedstructures in that for a determination of a deposition position toreceive deposition the entire position must possess data that indicatesthat material is to be present, (3) an averaged sized approach in thatdetermination of deposition may be based on the percentage of a givendeposition position for which the data indicates material is to exist.

In alternative embodiments the cell electrodes can take on differentforms ranging from porous structures to peripheral rings. For example, across of conductive material may extend to the center of a cell or aline of conductive material may be suspended in the center of a cell. Instill other alternatives the cell electrodes may be segmented andmultiple feeds used to apply a variety of potentials to a single cell.In some embodiments, the conductive material of the electrodes may beexposed to the electrolyte while in other embodiments they may beisolated from the electrolyte.

In still further embodiments, the cell electrodes may be provided with asufficient potential difference relative to the other electrodes that asignificant amount of gas may be produced (e.g. via hydrolysis orvaporization) that could help limit etching from the inactive cells. Ifbubble generation is found to be unproductive or otherwise bothersome,agitation or electrolyte flow may be used to sweep bubbles away suchthat problems with etching from active cells are minimized.

In various alternative embodiments, layer build up may occur from acombination of selective depositions of one or more materials from amulti-cell programmable mask. Other alternatives could use a combinationof selective depositions from a multi-cell programmable mask and fromone or more structure or device specific masks. In other embodiments,selective deposition from multi-cell programmable masks may be combinedwith blanket depositions. In still other embodiments, planarizationoperations may be used after deposition of all material for a givenlayer and/or intermediate to the deposition of all material for a givenlayer.

In various other alternatives, selective etching may be performed incombination with selective depositions and/or blanket depositions.Various electrochemical fabrication techniques that use etching aredescribed in the previously referenced U.S. Pat. No. 6,027,630 and inU.S. patent application Ser. No. 10/434,519, filed May 7, 2003 bySmalley, and entitled “Methods of and Apparatus for Electrochemicallyfabricating Structure Via Interlaced Layer of Via Selective Etching andFilling of Voids”. This patent application is incorporated herein byreference as if set forth in full. Selective etching In still otheralternatives, holes of varying depth or deposits of varying thicknessmay be generated by varying the pattern of active cells. The changing ofpatterns may occur in the middle of a deposition. The changing ofpatterns may occur during a shifting of the deposition pattern from onelocation to another. In other embodiments, the mask may be separatedfrom the substrate in the middle of a deposition to allow theelectrolyte to be refreshed.

In various other embodiments, specific cells can be turned on or offindependent of the switching on and off of other cells. In this regardcertain locations can undergo longer or shorter depositions as desired.For example, if an electrical short is detected, the shorted cell can beturned off. The shorted cell can undergo a reversal in polarity in anattempt to eliminate the nodule or other feature that caused the short.If necessary, the mask may be lifted away from the substrate to breakcontact with the nodule, be reseated, and then a reversal in polarityimplemented in an attempt to eliminate or reduce the nodule prior toattempting to complete the deposition

In various other embodiments, the cell control electrode may be replacedor supplemented by other control elements. Multiple cell electrodes maybe located in each cell. Some cell electrodes may be insulated by adielectric. The control elements can take various forms with the intentthat they allow cells to toggle between active and inactive states. Forexample, heating elements may be included in the cells to form gasbubbles that can block or significantly limit the ability of ions to beconducted to or from the substrate thereby causing formation of aninactive cell. The cell can be made active again in various ways. Forexample, the cell may be reactivated by separating the mask and thesubstrate and introducing a vibration, agitation, or flow of electrolytein the region of the cell to dislodge or otherwise remove or eliminatethe bubble. Bubble formation may be made to occur in a variety of ways.For example, bubble formation may occur by creating sufficient resistiveheat or radiative heat to vaporize a small quantity of liquid in theelectrolyte or by passing an electrical current through the electrolytewithin the cell so a portion of the liquid undergoes hydrolysis (i.e.from 2H2O to 2H2 and 2O2). Other control elements may be used to causethe movement of mechanical element from an open position (active) to aclosed position (inactive) via an electrostatic or magnetic force. Stillother control elements may use cooling to freeze or otherwise lower themobility of ion transfer through an inactive cell.

In some embodiments a surface of the dielectric forming the grid ofcells will contact the substrate to form a seal around each cell whilein other embodiments the dielectric forming the grid of cells will notcontact the substrate but will be located close enough to it (inproximity to it) to cause a reasonable amount of isolation betweendeposition and/or etching operations in adjacent cells (for example toyield an effective ratio of deposition height or etching depth in activecells to that in inactive cells of 5 or greater or even 10 or greater).In embodiments that use a bubble formation to create inactive cells,bubbles formed against the substrate may aid in forming a seal betweenthe inactive cell and any active adjacent cells. In still otherembodiments, the dielectric forming the grid of cells may haveindentations or ridges on its contact surface to inhibit completesealing between the mask and the substrate. This incomplete sealing maybe useful when bubble formation is used to inactivate cells as it mayleave small flow paths for displaced liquid to escape. In otherembodiments, cell energization (i.e. transition to and from active andinactive states) may occur in a predefined order. The predefined orderedmay be selected, for example, to minimize the risk of trapping excesselectrolyte (e.g. via bubble formation) within a portion of the mask.

In embodiments where, proximate positioning is used between a mask andthe substrate, instead of holding a given deposition/etching positionfor a time, then stopping deposition/etching, making a transition to anew position, and then restarting deposition/etching, it may be possibleto simply perform a continuous orbit within a desired deposition/etchingregion for a desired period of time. The orbiting pattern may beselected to give a desired pattern of differential deposition/etching.If the width of deposition/etching region is at least twice the width ofa cell it may be possible to achieve uniform deposition or etching if anappropriate orbiting pattern is selected.

While the disclosure herein has focused primarily on the use ofmulti-cell masks for deposition purposes, other embodiments may also beused to selectively etch material in a manner largely analogous to thetechniques used for depositing material with the distinction that inpartially overlapped etching operations corners of etched material maybe removed more quickly than planar regions and thus sharp corneredregions may become rounded. This is illustrated in FIGS. 36(a)-36(d).FIG. 36(a) shows a side view of a mask positioned over a substrate inposition for a first etching operation. FIG. 36(b) shows the mask andsubstrate after a first etching operation where the mask as been shiftedto the right for a second etching operation. FIG. 36(c) depicts theresult of the second etching operation where only vertical etching hasoccurred and the corner 932 remains sharp, while FIG. 36(d) depicts apossible result when a more isotropic etching occurs and where corner934 becomes flattened. This may be a disadvantage in some applicationsbut it may also be an advantage in other applications.

In some embodiments where the cells of the mask will be used foretching, it may be preferable to set the region width to somewhat largerthan an integral number of cell widths such that tolerances in size andpositioning ensure that overlapping etching regions do not initiallyoccur but such that small regions of separation will be readily removedby the etching operations and that any overlapping etching is minimized.

Multi-cell masks may be fabricated in a variety of ways including theuse of electrochemical fabrication on integrated circuits that act assubstrates, molding operations, or ablation operations (e.g. to shapedielectric materials), use of electrochemical fabrication (e.g. viadeposition specific masks) to form electrodes and conductive paths, andetching operations may be used to make passages, and the like. In someembodiments photoresist processing techniques may be used to formpatterned masks.

In some embodiments of the present invention a means for depositingmaterial may be used. This means may provide a selective deposition or ablanket deposition. This means may include a multi-cell mask or othermask if the deposition is to be selective. The means may include variouscomponents that are useful for applying a material to the substrate in avariety of ways, such as for example: (1) electroplating, (2)electrophoretic deposition, (3) electrostatic deposition (4) chemicalvapor deposition, (5) physical vapor deposition, (5) spraying such asthermal spray metal deposition, (6) flinging of a liquefied material ora material in a binder or other carrier, (7) spreading such as by brush,doctor blade, or roller, (8) ink jet deposition, (9) contacting,spinning, and drying or otherwise curing. Techniques for formingthree-dimensional structure using thermal spray metal depositionprocesses are described in U.S. Provisional Patent Application No.60/422,008, filed on Oct. 29, 2003 by Lockard, entitled “EFAB methodsand apparatus including spray Metal Coating Processes”. This applicationis incorporated herein by reference as if set forth in full. The meansmay take on various other forms or may be a combination of apparatusimplementing the above processes. The specific elements that may be usedwith the above noted processes, and variations thereof are wellunderstood. Other deposition means will be apparent to those of skill inthe art upon review of the teachings herein. Some alternative means maybe described in the various publications and patents incorporated hereinby reference.

In some embodiments of the present invention it may be possible toseparate the multi-cell masks into two or more pieces. For example, theportion of the mask that contacts the substrate may be formed on thesubstrate while the portion of the mask that contains the electrodes,and the like, may be contacted against an already adhered grid patternof dielectric material. The gird pattern of dielectric material that isadhered to the substrate may be formed from patterned photoresist,photopolymer or the like. Embodiments with such split multi-cell masksmay have the advantage of requiring less precise positioning of theactive part of the mask so long as the adhered portion is placed withadequate precision.

In some embodiments the controllable masks may be reduced to a singlecell that can be used to draw out a desired deposition much like a penis used to draw patterns one dot or line at a time. In still otheralternative embodiments, the single cell may be used to cause selectiveetching of various portions of a substrate or portions of a partiallyformed layer. In still further embodiments the grid of multi-cell masksmay be configured in a linear array much like some ink jet print headsare arrayed.

Various other embodiments of the present invention exist. Some of theseembodiments may be based on a combination of the teachings herein withvarious teachings incorporated herein by reference. Some embodiments maynot use any blanket deposition process and/or they may not use aplanarization process. Some embodiments may involve the selectivedeposition of a plurality of different materials on a single layer or ondifferent layers. Some embodiments may use blanket depositions processesthat are not electrodeposition processes. Some embodiments may useselective deposition processes on some layers that are notelectrodeposition processes. Some embodiments may use nickel as astructural material while other embodiments may use different materialssuch as gold, silver, or any other electrodepositable materials that canbe separated from the copper and/or some other sacrificial material.Some embodiments may use copper as the structural material with orwithout a sacrificial material. Some embodiments may remove asacrificial material while other embodiments may not. In someembodiments, the depth of deposition will be enhanced by pulling theconformable contact mask away from the substrate as deposition isoccurring in a manner that allows the seal between the conformableportion of the CC mask and the substrate to shift from the face of theconformal material to the inside edges of the conformable material.

In view of the teachings herein, many further embodiments, alternativesin design and uses of the instant invention will be apparent to those ofskill in the art. As such, it is not intended that the invention belimited to the particular illustrative embodiments, alternatives, anduses described above but instead that it be solely limited by the claimspresented hereafter.

1. A process for forming a multilayer three-dimensional structure,comprising: (a) forming a layer of at least one material on a substratethat may include one or more previously deposited layers of one or morematerials; (b) repeating the forming operation of “(a)” one or moretimes to form at least one subsequent layer on at least one previouslyformed layer to build up a three-dimensional structure from a pluralitylayers; wherein the forming of at least one layer, comprises: (1)supplying a substrate on which one or more successive depositions of oneor more materials may have occurred; (2) supplying a multi-cell mask,wherein each cell is separated from other cells by a material, whereinthe cells of the mask comprise independently controllable electrodes,and wherein a pattern of dielectric material extends beyond the cellelectrodes for contacting the substrate and for forming electrochemicalprocess pockets when such contact is made; (3) bringing the multi-cellmask and the substrate into contact such that electrochemical processpockets are formed having a desired registration with respect to anyprevious depositions and providing a desired electrolyte solution suchthat the solution is provided within the electrochemical processpockets; and (4) applying a desired electrical activation to at leastone desired cell electrode, to the substrate, and to any other desiredelectrode or electrodes, such that a desired material is selectivelydeposited onto the substrate.
 2. The process of claim 1 wherein there isno other desired electrode or electrodes that are to be activated. 3.The process of claim 1 wherein at least a portion of the dielectricmaterial that extends beyond the cell electrodes comprises a conformablematerial.
 4. The process of claim 1 wherein the applying results inelectroplating of the desired material on to the substrate.
 5. Theprocess of claim 1 wherein the formation of the three-dimensionalstructure comprises at least the deposition of two different materialsduring the formation of at least a portion of the plurality of layers.6. The process of claim 1 wherein a plurality of the cells of themulti-cell mask comprise an electrodepositable material that may bedeposited during the applying operation.
 7. The process of claim 1wherein the formation of a desired pattern of material on a given layercomprises a plurality of selective deposition operations using themulti-cell mask wherein at least a portion of the depositions utilize acell whose deposition position is offset between at least two depositionoperations.
 8. The process of claim 7 wherein at least a portion of theoffsets of a cell result in locating the cell to a deposition positionthat partially overlaps a previous deposition position associated with aprevious registration of the cell.
 9. The process of claim 7 wherein thecell is made active when located at a portion of its depositionpositions and is inactive when located at a portion of its depositionpositions on a given layer.
 10. The process of claim 9 wherein aresolution of a layer is better than that of a net area defined by thelocations at which a given cell is positioned during the formation of alayer.
 11. The process of claim 7 wherein the cell is made eitherinactive or active when located at each deposition position to which itis located during deposition of a given material during formation of agiven layer.
 12. The process of claim 11 wherein a resolution of a layeris substantially defined by a net area defined by the locations at whicha given cell is positioned during the formation of a layer.
 13. Theprocess of claim 7 wherein at least a portion of the offsets of a cellresult in locating the cell to a deposition position that issubstantially in registration with a deposition position from a previousregistration of the cell on the given layer.
 14. The process of claim 7wherein at least a portion of the offsets of a cell result in locatingthe cell to a deposition position that does not substantially overlap adeposition position from a previous registration of the cell on thegiven layer.
 15. The process of claim 1 wherein the multi-cell maskcomprises a plurality of rectangular cells laid out in a rectangulargrid.
 16. The process of claim 15 wherein the rectangular cells aresquare.
 17. The electrochemical fabrication process of claim 1 wherein,the operation of at least a portion of the cells of the multi-cell maskis tested by electroplating material using the mask and examining theresulting depositions.
 18. The electrochemical fabrication process ofclaim 17 wherein any cells found to be faulty are labeled and the use ofany faulty cells is avoided.
 19. The electrochemical fabrication processof claim 6 wherein deposition from cells is tracked.
 20. Theelectrochemical fabrication process of claim 6 wherein at least areportion of the cells are redressed by replenishing theirelectrodeposition material.
 21. The electrochemical fabrication processof claim 20 wherein any electrochemical deposition material remaining incells to be redressed is removed prior to replenishment of theelectrodeposition material.
 22. The electrochemical fabrication processof claim 7 where a planarization process occurs between at least twooffsets prior to deposition thickness reaching a desired depositionthickness for the layer.
 23. A multi-cell mask, comprising a pluralityof independently controllable cells, wherein each cell is separated fromother cells by a material, wherein the cells of the mask compriseindependently controllable electrodes, and wherein a pattern ofdielectric material extends beyond the cell electrodes for contacting asubstrate and for forming electrochemical process pockets when suchcontact is made.
 24. An apparatus for forming a multilayerthree-dimensional structure, comprising: (a) a substrate on which one ormore successive depositions of one or more materials may have occurred;(b) a mask having multiple cells, wherein each cell is separated fromother cells by a material, wherein the cells of the mask compriseindependently controllable electrodes, and wherein a pattern ofdielectric material extends beyond the cell electrodes for contactingthe substrate and for forming electrochemical process pockets when suchcontact is made; (c) a computer controlled stage for bringing themulti-cell mask and the substrate into contact such that electrochemicalprocess pockets are formed having a desired registration with respect toany previous depositions and providing a desired electrolyte solutionsuch that the solution is provided within the electrochemical processpockets; (d) at least one power supply for applying desired electricalpower to the substrate, to selected cell electrodes, and to any otherelectrodes required to cause selective deposition onto the substrate;(e) at least one computer programmed for repeatedly controlling thestage, for controlling selected cell electrodes, and for controlling thesupply of power from the power supply to cause selective deposition ontothe substrate to deposit at least portions of a plurality of layers ofmaterial on previously formed layers when forming a desired structurefrom a plurality of layers.
 25. The apparatus of claim 24 wherein thereare no other electrodes.